CRI, the colour rendering index, is a score out of 100 for how truthfully a light shows colour. 80 is the floor for a home, 90 is what you want anywhere you look at food, faces or paint, and anything unmarked should be assumed to be 70 and left on the shelf. Brightness gets all the attention on the box. CRI is the number that decides whether your kitchen looks like your kitchen at night, and almost nobody checks it.
We have been selling lighting for 41 years, and the bulb complaints that are hardest to put into words are rarely about brightness. They sound like 'the room looks grey', or 'my skin looks ill in the bathroom mirror', or 'the paint is a different colour to the one I chose'. Very often that is a colour rendering problem, and the number was printed on the packaging all along.
What CRI actually measures
Every light source has a colour, which is the Kelvin number you may already know about (see warm white vs cool white). CRI is different. It asks: under this light, do the colours of the things in the room look the way they would under a reference light of the same warmth? Daylight and the old incandescent bulb sit at or near 100, because they contain the whole spectrum and give every pigment something to reflect. An LED makes white by mixing a narrower set of wavelengths, and if a colour in the room needs a wavelength the LED does not produce, that colour goes dull.
The test behind the number is run by the CIE, the international lighting body. The lamp is shone on a set of standard colour samples and the shift in each one is measured. The headline figure, sometimes printed as Ra, averages the first eight samples, which are all pale, muted tones. That averaging is why an 80 and a 90 can look further apart than ten points suggests, and it is also why the number has a blind spot, which we will come to.
What 70, 80, 90 and 95 look like in a room
| CRI | What it looks like | Where it belongs |
|---|---|---|
| Under 70 | Reds go brown, skin goes sallow, wood looks flat. Old fluorescent tubes and the cheapest LEDs | A garage, a loft, nowhere you look at anything |
| 80 | The everyday LED. Colours are recognisable and a room looks normal, with reds and skin tones slightly softened | Hallways, landings, utility, general ceiling light. The minimum for a home |
| 90 | Reds come back, skin looks like skin, a bowl of fruit looks worth eating | Kitchen worktops, bathroom mirrors, dining tables, anywhere with art or strong paint colours |
| 95 and above | Close to daylight. The difference from 90 is real but small, and it costs | Studios, retail, a dressing table if you are particular |
Our position is simple. 80 is the floor, and it is a fine floor for the lights you walk under rather than look at. Anywhere you look at something, at a face, a plate or a wall you spent a weekend painting, buy 90. The gap between 80 and 90 is the biggest jump on the scale for the money, and it is the one people notice without being able to name it.
The blind spot: R9 and the colour red
Because the headline number averages eight pale samples, a lamp can score 80 and still be poor at one colour in particular, and that colour is almost always red. Saturated red has its own test sample, R9, and it is excluded from the average. It is also the hardest colour for an LED to produce and the one that carries the most in a home: skin, wine, tomatoes, terracotta, a red front door, most wood, most brick.
So an 80 CRI lamp can have an R9 in the teens, which is why a bathroom can be bright and still make you look like you have been ill for a week. If a maker quotes R9 at all, they are proud of it, and that tells you something. A lamp described as 'CRI 90' will almost always have an R9 above 50, which is where skin starts looking like skin. That is why the mirror needs two figures. Our warm white guide suggests around 4000K there, for a neutral colour of light; CRI 90 is what makes the reds in skin render truthfully under it. A cooler bulb with a low CRI still renders red poorly, so check both numbers, which are printed separately.
Why CRI matters more than brightness
Lumens are how much light. CRI is what the light does when it lands. You can add lumens by adding a lamp. You cannot fix a low CRI with more of it; a brighter 70 CRI light is a brighter grey room. Most houses have more than enough lumens already, and the rooms that feel wrong feel wrong because of colour, both the Kelvin number and the rendering. If you are choosing between a 600 lumen bulb at CRI 80 and a 470 lumen bulb at CRI 90 for a table lamp or a mirror light, take the 90 every time. If the room then needs more light, put it on a second source, which is better lighting anyway (see how to layer lighting in a room).
Where CRI 90 earns its money, and where 80 is fine
- Kitchen worktop and hob: 90. You are judging whether meat is cooked and whether the fruit has turned. Under-cabinet lights and the downlights over the prep area are the first place to spend.
- Bathroom mirror: 90, from the sides, at around 4000K, the colour temperature our warm white guide suggests there. Make-up matched under a low-CRI mirror light looks wrong outdoors. Our mirror lighting guide covers the position; CRI is the number to pair it with.
- Dining table: 90. Food and faces, on show for an hour, close up.
- Living room lamps: 90 if you have strong colour on the walls or art you care about; 80 is acceptable for a soft ambient glow.
- Hall, landing, stairs, utility, garage: 80. You pass through. Spend the money elsewhere.
- Outside: 80. Nobody is checking their complexion on the patio.
- Wardrobe and dressing table: 90 and, if you are serious about matching navy to black, 95.
How to find it on the box, and what to do if it is not there
Look for 'CRI' or 'Ra' followed by a number, usually on the side of the packaging or in the specification on the product page. On our site it sits in the specification tab as CRI. If a lamp gives no figure at all, treat it as 70. Makers who have paid for a 90 say so, in large type, because it is the thing that separates a decent LED from a cheap one. Silence is a number too.
The words are no help. 'Warm white', 'natural', 'daylight' and 'true colour' describe the Kelvin number, or nothing at all. A 'daylight' bulb at 6500K can have a CRI of 70 and it will make a bathroom look like a hospital corridor. Read the number, ignore the adjectives.
Where our own range sits, honestly
Our standard replacement lamps, the GU10s, candles, golf balls and G9s that most fittings take, are CRI 80. That is the right floor and the right price for a hallway or a run of ceiling lights, and we would not pretend they are more than that. Where we go to 90 is in fittings with the LED built in: the Astro bathroom range, the Astro Can spotlights and track heads, and the Collingwood H2 Pro downlights are all 90 or above, which is exactly where you want it, over the worktop and at the mirror.
Check the colour temperature on the same specification, because CRI 90 comes at different Kelvin figures. The Astro Minima Round fire-rated downlight (£66.55, checked 19 October 2026) is CRI 90 at 2700K, and the Astro Can 50 spotlight (£93.84, checked 19 October 2026) is CRI 90 at 3000K, which suits a worktop. Beside the mirror, the Astro Palermo 600 wall light (£169.05, checked 19 October 2026) is CRI 90 at 3000K and the Astro Kyoto wall light (£145.59, checked 19 October 2026) is CRI 90 at 2700K, so the rendering is there but the cooler figure is not. The Astro Mallon ceiling light in bronze (£178.02, checked 19 October 2026) is CRI 90 and switches between 2700K, 3000K and 4000K. It is the closest we list to both figures in one bathroom fitting, though it is a ceiling light rather than a mirror light.
If you want 90 in a replaceable lamp, ask us before you buy and we will point you at the right one for the cap you have; E14 or E27 is usually the first question. And whatever the CRI, buy a dimmable one where the switch allows it, because the second half of colour is how much of it there is.
The short version
- CRI is a score out of 100 for how truthfully a light shows colour. Kelvin is the colour of the light itself; the two are separate.
- 80 is the floor for a home. 90 wherever you look at food, faces, art or paint. Unmarked means 70, walk away.
- The headline number hides red. Look for R9 if it is quoted; a CRI 90 lamp almost always renders skin and food properly, a CRI 80 may not.
- More lumens do not fix a low CRI. A brighter low-CRI room is a brighter grey room.
- Spend on 90 at the kitchen worktop, the bathroom mirror and the dining table. Save on hallways, landings and outside.
- At the mirror you want two figures: CRI 90, and around 4000K for the colour of the light. Check both on the specification.
Frequently asked questions
What is a good colour rendering index?
80 is the minimum worth buying for a home and is fine for general ceiling light in hallways and landings. 90 is a good CRI and the right choice for kitchens, bathroom mirrors (at around 4000K) and dining tables. 95 and above is close to daylight and only worth paying for where colour matching matters, such as a dressing table or studio.
What does a CRI of 90 mean?
A CRI of 90 means that, across a standard set of colour samples, the colours shift only slightly from how they look under a reference light of the same warmth, scoring 90 out of a possible 100. In practice reds, skin tones and wood look natural. It usually also means a decent R9 score, the separate red sample, which is where CRI 80 lamps tend to fall down.
Is 80 CRI good enough?
For a hallway, landing, utility room, garage or general ceiling light, yes. For anywhere you look closely at colour, such as a kitchen worktop, bathroom mirror or dining table, no; go to 90. The step from 80 to 90 is the most noticeable on the scale for the money.
Can you tell the difference between 80 and 90 CRI?
Yes, side by side, and especially on reds: skin, food, wood and terracotta look flatter under 80. Most people cannot name what is wrong under an 80 CRI lamp, they just feel the room looks grey or that they look tired in the mirror. Under 90 those colours come back.
Which LED lights have a high CRI?
Fittings with the LED built in from the better makers are commonly CRI 90, including the Astro bathroom range, Astro Can spotlights and Collingwood H2 Pro downlights. Standard replacement LED bulbs are usually CRI 80. Look for CRI or Ra on the box; if no figure is given, assume 70.
Is 100 CRI possible?
Daylight and incandescent bulbs are the reference and sit at or near 100. Some LEDs reach 97 or 98, but 100 across every sample is not something you will find in a domestic LED, and the difference between 95 and 100 is not visible in a home.
How is CRI calculated?
The lamp is shone on a set of standard colour samples and the shift in each colour is measured against a reference light of the same colour temperature. The published CRI, also written as Ra, is the average of the first eight samples, which are all pale tones. Saturated red, R9, is measured separately and is not in the average.
