5 Steps to Properly Replacing 50w Halogens with the Best GU10 LED bulb

Do you know how to find the best GU10 LED bulb to replace your 50w halogens?

Buying spotlights for your home used to be so simple. You knew they would be bright, you knew they were all dimmable and you knew the quality of light that they emitted would create a lovely warm glow and inviting ambience in your home. The only choice you had to make was whether to go for a GU10 or MR16 fitting.

However, now we have moved onto LED, things have become more confusing. I’ll actually go even further than that, things have become utterly bewildering for customers. Did you know that even if you have invested a considerable amount of time and energy into researching the industry and products, you still stand very little chance of buying an LED spotlight that can actually replace a 50w halogen?

Whilst every ‘specialist’ LED retailer will proudly tell you that their product will be a like-for-like replacement for a 50w halogen, the truth is that virtually none of them are a genuine replacement. I currently only know of two products that genuinely are 50w halogen replacement LED spotlights. That’s quite shocking when you consider the thousands of products all advertised as halogen replacements. To ensure that you get the best spotlights you can, here are the five things you need to look out for when replacing halogens with GU10 LED’s:

1) Colour Temperature

Firstly, ‘warm white’ is NOT a colour temperature. It is a description of a colour that can vary significantly from company to company and product to product. Companies use this inaccurate and vague term to insinuate that their product will emit a similar warm colour and feel to that of a halogen, which is often not the case.

Take a look at these three images:

First, we have a 50w halogen. In the middle, an LED spot sold by a leading online LED retailer very visible in Google searches, that describes this spot as a ‘perfect halogen replacement’ with a colour of warm white. Finally, we have a genuine 50w halogen replacement 7w GU10 LED.

50W Halogen – 2700k

50W Halogen

4w LED Spot – 3000k


From the images you can see the ‘perfect halogen replacement’  LED spot in the middle is in no way comparable to the halogen or the 7w LED spot. This is because:

  • It is a completely different colour temperature
  • It has a low CRI score (we’ll come to that later)

When you actually pay attention to the colour temperature of the ‘perfect halogen replacement’ LED spot (which the company in question don’t publish on their website), it isn’t ‘warm white’ at all as claimed. It’s actually 3000k, a much more whiter light that I find is quite harsh and uninviting for living areas.

One reason a company might describe 3000k as ‘warm white’ (whilst not actually publishing the colour temperature) is because the higher the colour temperature, the lower lumen rating you need for comparative levels of illumination. Your eye responds differently with variable sensitivity to colours in the spectrum and 200 lumens of a natural white spot (3000k) will appear “brighter” than 200 lumens of warm white (2700k) unit, meaning the retailer does not need to purchase an LED Spot with a high performance chip, making it cheaper.

2700k provides that nice cosy, relaxing, winding down at the end of the day ambience and natural white for work tasks in the kitchen, shaving and make up in the bathroom

Lighting choices are a very personal. Individual preferences do vary; different people and age groups will have very different opinions on which they prefer.

So make sure when you are looking to replace a halogen, ignore the term ‘warm white’ and look for the colour temperature of 2700k.

Colour Temperature Guide

2) Colour Rendering Index

This is the one area where virtually all LED’s are lacking. CRI is a measure out of 100 that tells you how effective that light source will be at showing the true colour(s) of objects in your home. The closer to 100 you get, the better that product is at rendering the true colours. The important factor here is that a 50w halogen has a CRI of 100. This means it’s perfect at rendering colour and everything in your home will look it’s best under these spotlights. The vast majority of LED spotlights on sale only have a CRI of around 80, which means that the ability of these LEDs to render colour efficiently will be roughly 20% lower than the halogen – quite a considerable drop.

If you take a look at this image, the lamps are identical in terms of colour temperature and lumens, but look at the difference a drop of 20 CRI had on the colours of the play matt and wooden floor?

60W Incandescent 2700K – 100 CRI

60W Incandescent Bulb

10W LED Bulb 2700k – 80 CRI

10W LED Bulb Low CRI

Now take a look at these two photographs:

LED Lighting with 2700K and 95+ CRI 

95 High CRI LED

LED Lighting with 2700k and 80 CRI


Pay particular attention to the brown leather chair. You can clearly see that the definition in the appearance of the colours is far superior under the high (95+) CRI lighting.

Now have a look at these three photographs of a mat on some flooring:

50W Halogen – 2700K, 100 CRI

50W Kids

4W LED Spot – 3000k, 80 CRI

4W Low CRI

Compare the CRI of a 50w halogen and a 95 CRI LED spot both with a colour temperature of 2700k, with the “perfect halogen replacement” 4w LED spot at 3000k with only 80 CRI. Can you see the difference that the wrong colour temperature and low CRI have on the colour of the flooring and the mat? The 4w LED Spot creates a sterile, uninviting atmosphere whereas the 50w halogen and 7w LED spot create a lovely warm and welcoming environment filled with vibrant colours.

 Here are three more images to confirm this point:

50W Halogen

50W Halogen

4W LED Spot 

4W Low CRI

Compare the difference between the 4w LED spot with its sterile and sanitary colours with the vibrant and warm colours of both the 50w halogen and 7w LED spot. If you’ve spent a considerable amount of time and money on furniture and furnishings for your home, wouldn’t you want it to look as good as it possibly could? Then why for the sake of a few pounds per lamp would you settle for poor quality lighting?

When you are looking at lighting and see an LED spotlight advertised as a ‘perfect’, ‘like for like’ or ‘direct replacement’ for a halogen, you need to ensure that the CRI score is at least 95. If not, it cannot be a genuine halogen replacement. Some companies don’t even publish a CRI figure for their LED products, which I find astonishing, so avoid these products and companies. Remember: to genuinely replace a halogen, an LED must have CRI of at least 95 (combined with a colour temperature of 2700k).

3) Lumens 

The required lumens you need to replace a 50w halogen are dependent on firstly getting the colour temperature and CRI right. If you have found an LED GU10 with 2700k and CRI of 95 or more, you will only require lumens of around 350.

4) Beam Angle

This is simple: a traditional 50w halogen has a beam angle of 38 degrees, so you just need to find an LED spotlight that matches this.

However, you can get LED’s with a much wider beam angle, up to 135 degrees. You just need to decide what works best for you and the room that you are installing them in. From my experience, 38 to 60 degrees works in the vast majority of applications.

5) Lifespan

A high quality LED spotlight will have a maximum lifespan of around 25,000 hours and no more. Because the brightness of an LED gradually decreases over time, the lifespan of an LED lamp is calculated to the point where at least 70% of useful lumens still remain. That means at the point where an LED has lost 31% of it’s useful lumens, that is the time it should be deemed ‘failed’.

Amazingly, some retailers still claim that their LED products have a lifespan of 50,000 hours. I’ve yet to see any of them publish a comprehensive and credible test report proving it. Yes an LED chip can last 50,000 to 100,000 hours, but the chip will not emit enough useful lumens to be bright enough to do the job ‘as described’. The other critical components of the LED lamp, such as the power supply or driver, will not last 50-100k hours either.

The fact is that an LED spotlight has a maximum lifespan of 25,000 hours and there are credible test reports to back this fact up. No reputable manufacturer of retailer would claim any more than this.


If you follow the directions below, then you will find the best GU10 LED Bulb LED  to replace your 50w halogens.

Wattage 7Watt – 10Watt
Colour Temperature 2700K
Colour Rendering Index (CRI) 95+
Lumens 345+
Beam Angle 38-60
Lifespan 25,000 Hours
Expect to pay £13 for a dimmable LED Spot

If you would like further advice on LED spotlights from recognised industry experts, don’t hesitate to call us on 01484 609759 or e-mail customerjoy@well-lit.co.uk.

If (like many) you just want a trouble-free halogen replacement bulb, our 7w GU10 LED comes with a 365-day money-back guarantee. We also stock an even brighter 9w bulb with a GU10 fitting.

Chris Stimson


34 thoughts on “5 Steps to Properly Replacing 50w Halogens with the Best GU10 LED bulb

  1. Hi, Thanks for clarifying much of the LED GUI mess.

    One aspect you haven’t commented on is physically replacing bulbs.
    I have some bulbs in fittings that are hard to access. I can replace halogen bulbs, with a flat glass front, by using a small plastic suction pad. This makes the job easy.
    I have not found any LED GU10 bulbs that are a perfect fit AND have a flat glass front I can use a suction pad with. It make replacing the bulbs much, much harder.

  2. Hi, Thanks for clarifying much of the LED GUI mess.

    One aspect you haven’t commented on is physically replacing bulbs.
    I have some bulbs in fittings that are hard to access. I can replace halogen bulbs, with a flat glass front, by using a small plastic suction pad. This makes the job easy.
    I have not found any LED GU10 bulbs that are a perfect fit AND have a flat glass front I can use a suction pad with. It make replacing the bulbs much, much harder.

  3. Hi, I have a set of 9 M16 halogens fitted to a dimmable circuit and controlled by two switches – either end of the same room. I want to switch to LEDs and understand I’d need to replace the transformers of the M16 units to LED , dimmable friendly transformers, as well as checking that there was still enough load being drawn through the circuit to make the dimmers operable. However, I’ve been told that simply replacing he transformers with a GU10 fitting would work.
    My question is whether this would work on the same dimmable circuit without me needing to upgrade or change the dimmer switch ?

  4. I have the same question as someone that someone else had in September that was never answered.

    “Very informative article. I have a question however. The thing I love about halogen spotlights is that when you dim them right down the light they give off is a lot warmer than when at full power. This is an effect I love for setting the mood and being less intrusive when having them dimmed for meals or watching TV. Do LED spotlights replicate this look?
    All your pictures show the comparison at full output but what about when they are dimmed down?”

    Would love to know the answer to this as it’s my key problem.

    1. Hi,

      Thanks for the comment. Our 7w and 9w LED GU10’s now incorporate Dim to Warm technology. This means the colour gets warmer as you dim them down just like your old halogens. We also offer a money backg guarantee if you are not completelt satisifed, you can get your money back !

  5. I have downlighting in our bathroom using GU10 Halogen 50W warm white bulbs. The lamp units have been fitted through from the attic, and being open at the top they attracts flies from the attic that keep getting inside the lights. Although they obviously die from the heat of the light, over time they start to look very unsightly. To stop flies getting inside the lights I would like to cover them in the attic, but am worried that the heat from the halogen bulbs could start a fire. I am therefore wondering whether LED bulbs might be the solution. I therefore have the following questions.
    1. Do halogen LED bulbs get hot?
    2. What would be the equivalent LED bulb (I wouldn’t mind them being slightly brighter.

    1. Hi, thanks for your comment.

      1) LEDs do get warm, like any light source, the more you restrict air flow around them, the shorter their life will be. That said you probably need to look at a fully enclosed fitting, which means nothing can get inside, including moisture and air.

      2) Our 7w GU10 LED is the equivalent of a 50w halogen.


  6. Hi.
    I currently have a long kitchen with 18 50W spots, 10 of which have now stopped working. Seems a good time to replace with LED’s.
    Do I need an LED driver for each lamp ?
    Can you supply all I need to do this replacement.(£££££’s). I think as it’s a kitchen the LED’s should be 3000’s.
    Presumably I would need to replace the bulb holders as well ?
    Anything else I need to know ?

  7. Very informative article. I have a question however. The thing I love about halogen spotlights is that when you dim them right down the light they give off is a lot warmer than when at full power. This is an effect I love for setting the mood and being less intrusive when having them dimmed for meals or watching TV. Do LED spotlights replicate this look?
    All your pictures show the comparison at full output but what about when they are dimmed down?

  8. In the interests of sustainability, can an existing MR16 12v transformer that causes flickering when feeding just one new LED 12v lamp (because they require a minimum 10 watt load), now be rewired to deliver 12v to two or more LED 12v lamps in parallel thus drawing more current through the existing transformer and hence cure the flickering problem and save our money and precious environment? Obviously the existing transformer must not be loaded beyond its typical 50watt capacity.

  9. Thanks for your excellent explanation on LED spots. Im glad it isnt just me going mad, Ive been going round in circles with all the variations and inconsistencies in light quality trying to find something nice!

    It looks like your lamps might hopefully be the solution. One further question though; the other problem I have with the LED spots is they are not very spot-ty, ie the light is much more diffuse and unfocused than the halogens which is not so nice for mood effect.

    How are your 7/9w in that respect? Do you know if anyone makes one with a proper tight spot?

    Many thanks.

  10. I want to replace MR16 Halogens in our 3 bathrooms with LED GU 10s and have found your article extremely useful in understanding the relationships between the two types of light bulb.

    I have one question as the light fittings in the bathrooms are slightly different to the halogen fittings in all other living spaces as the halogen glass is not flush with the bathroom’s ceiling light fittings but are raised about 25mm within a metal tube.

    Will this difference effect the angle, colour etc when choosing the LED replacement bulb?


  11. Hi,
    can you advise on the best transformers and dimmer switches that work with the “7w GU10 with 345 lumens”? I want to replace my hallogen downlights in 4 sections or blocks – each between 4 and 8 lamps.
    I find it difficult to get hold of an electrician with experience in dimmable or LED’s. Most claim, “no problem”; but then they don’t even know what a CRI value is.

    1. Hi, we don’t recommend any transformers I’m afraid as we don’t sell MR16 Spotlights, but for dimming with our GU10 LEDs we recommend the Varilight V-pro range

  12. Hi there. A great article. I wish I had red this article several years ago! I have wasted so much time on buying rubbish replacement LED spots. Many thanks, Steve.

  13. Hi, I have lamps in glass on the wall with 50w gu10, tried 11w led but the light does not enter the room very well. The 50w lights through the glass and the led’s only downwards. What can i replace the 50w with and still have good light in the hole room ?

  14. I’m having difficulty lighting artwork in the same space. I have 3 walls with angled recessed spots using 50W halogen GU10 bulbs that look great. The painting on the fourth wall has an art bar fixture with sockets for 4 max 25W standard type B bulbs. I thought that 4×25 would be plenty bright enough, but it seems not very close to the 50W halogen bulbs. So…I’m wondering if I can get brighter lights using LED bulbs (so as to stay under the 25W maximum the fixture allows), but would want the combination of the four bulbs to be roughly equivalent (or slightly brighter than the GU10), with the same color temperature, able to fit the type B socket, and dimmable since they are all on the same circuit. Thoughts? Recommendations?

    1. Hi, thanks for the message. We have two GU10 LED Spots, a 9w version with 500 lumens that is brighter than a 50w halogen and a 7w version with 345 lumens that replaces a 50w GU10. It would be great if you could send me an image of the light fitting you are using and the layout of the area so that we can properly make a suggestions as to what might be the best solution – customerjoy@well-lit.co.uk

  15. Very illuminating (!) Thank you. Your article leads to one conclusion though. I have 6 non-dimmable MR16s to replace in one room, and 9 dimmable in another. The latter are in mounts which tilt and swivel and have less ‘headroom’ one MR16 I tried wouldn’t fit. Do you have any recommendations regarding these two types please?

    1. Morning Mr Milner. I’m afraid we choose not to sell MR16 (GUX5.3) fitting LEDs. The reaons for this is that with MR16’s LEDs, each fitting usually requires a specialist LED transformer. The actual LED Spotlight and the transformer need to be compatible and you will need an electrician to fit the transfomers. It’s far easier and cheaper to get an electrician to simply change the fittings to GU10 and purchase GU10 spotlights. A GU10 spotlight contains an internal transformer so there is no need for external ones. Things also get a little more complicated with dimmable MR16 LED Spots too.

  16. Hi I have replaced my 50w halogen bulbs but after a while the L E Ds start to flicker. All my lights have individual transformers.

    1. LEDs flickering suggests that you do not have the correct transformers. If you just replaced the halogen MR16 bulbs with LEDs without changing the transformers, that’s your problem. The halogen transformers usually work with a minimum load of c.10 Watts – the LEDs don’t reach that. You need to replace the transformers with LED specific transformers.

      1. Forgot to mention that Flickering may also be caused by an incorrect dimmer switch – for the same reason. You need to have a LED ‘friendly’ dimmer switch that functions on lower loads.

  17. What an extremely well written and excellently presented article on the subject of all aspects of LED lighting to suit the home.

    Thank you very kindly,


  18. My bathroom light has 3 halogen globe 50w bulbs, 2 no longer are giving me light. I just purchased globe LED for Life 50w GU10 base, is there a special way to remove halogen bulbs that need to be replaced and do I have to wear rubber gloves when I install new bulbs.

    1. You should just be able to push in slightly and turn to remove. Reverse the procedure for installation.

      You will not need gloves – these are necessary for halogen because human skin does something to the bulb that significantly shortens its lifespan.

      Caution – if you have a 50w halogen, a 50w LED would be too big. You probably only need something in the 5w to 10w range to replace the halogen.

      As suggested you should either read up on substituting/consult the manufacturers guidelines for substitution/or refer to a qualified electrician.

  19. Interesting article.

    Regarding point 3, I tried a branded GU10 5W LED with 2700K colour temperature and a CRI >80 which had lumens of 350 and it was far too dim compared to the existing MR16 50W halogens it was replacing.

    I then tried a branded 7W GU10 LED, again with 2700k colour temperature and a CRI > 80 but rated at 480 lumens. This was much better but still a little dim compared to the current 50W halogens.

    I’m wondering how a GU10 LED with only 350 lumens can possibly replace a 50W halogen, even if the colour temperature is the same and the CRI is comparable.

    1. Interesting question, are we comparing like for like and how are we measuring things?

      What is the lumen output of the original MR16 lamp(s), all are not the same.
      The low voltage MR16 lamps originally designed for projectors have a comparatively thick filament, part in order to provide the ruggedness required for in operation due to vibration, try a standard 240v mains type with a far thinner filament and it would fail very quickly.

      The thicker filament of the lower voltage unit enables the filament to be run at a comparatively higher temperature, effectively producing more
      output. Even the USA 110volt versions of GU10 lamps produce more output than the UK versions due to the thicker filaments.

      Consider also that there is a tolerance spread from the individual lamps, we’ve observed variance in the order of over 40%; two lamps for a Pound will tell you a lot.

      Now consider how are we determining the differences, measuring equipment or the good old mark 1 eyeball and what are we actually looking at, the lamp or
      the effect? And are we comparing a room totally with halogen and then totally with LED lamps or half and half? The later will noticeably be different to most people. Not practical to measure lumens but it is easy and practical to measure lux, the amount of light falling on a surface which is what we really want isn’t it?

      Generally it is the effect of the light in the room we are observing, colour temperature, accurate colour reproduction and brightness all enter into it.
      Seldom do we actually observe the lamps directly, not unless we have some suitable form of eye protection, though surprisingly with new LEDs installed
      this is the first thing some people do, direct observation with the resulting issues.

      Those helpful chaps over in the EU have come up with comparative tables, easily found on the web, and 50 old watts for a GU10 lamp is equivalent of
      330-400 lumens or 350-450 useful lumens.

      You don’t reckon from your experiences, in your particular situation, that 350 lumens is the equivalent of the 50w halogens you have; who am I to
      argue? It is your personal preference at the end of the day isn’t it? It is what you find satisfying in your particular situation, might not suit me or
      the next man but it is your personal choice of what you want.

      Life was so simple when it was a choice of 40, 60 or 100 watts sir, now the choices are virtually limitless.

      This is why we offer a 365 day returns policy on all orders as standard. This means you can make a purchase from us, live with the lamps for a while and then decide if they are suitable or not.

      Thank you for the interesting question and i hope we have answered it for you !

  20. Hi, Can you please advise me which GU10 led I should purchase for our 4 new outside wall lights.
    They are polished metal which need up & down lighting.

    We would like them to be very bright and need to know what degree angle is best to get

    Many thanks

    Joe Phillips

    1. Hi Mr Phillip,

      The brightest lamp we do is our 9w LED Spot which has 500 lumens which is very bright and often too much for most applications. The most popular GU10 we sell is the 7w GU10 with 345 lumens, we have had many customers use this lamp in exactly the same outdoor light fitting that you have described. The beam angle is 36 degrees on both products and we feel this is optimum. It produces a nice spread of light without losing the intensity of light.

    1. Hi, sorry for the delay in responding. The best thing to do is either call your local electrical recycling centre or you can find electrical recycling units units in some supermarket car parks.

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