You may see some bulbs with a CRI number listed on their specs. What does this mean, and how can you use it in your home or business?

CRI Explained

CRI (or ‘Colouring Rendering Index’) is a scale running from 0-100, which rates the ability of artificial white lights to accurately display colour.

  • An index score of 100 means that the light entirely reflects natural lighting.
  • An index score of 90 is exceptional, getting very close to natural daylight (with most people being unable to distinguish between 90 or 100).
  • An index score between 80-90 renders colour accurately, with most LED bulbs being able to achieve this score easily.
  • An index score of below 79 will steadily drop in accuracy, with below 50 starting to look noticeably inaccurate.

Have you ever looked in the mirror in a public bathroom or office and thought you looked far more off-colour than you did when you left the house? The culprit is often lighting with a low CRI rating! Older LEDs used to have typically quite poor CRI ratings, but as the technology has improved they can now be relied upon to really shine in this area.

For most domestic applications, CRI isn’t incredibly important (although we’ve listed a few key areas later in this article!), but it’s important to match the

What CRI Rating Should Go Where?

  • In places where colour accuracy is really important, such as studios, galleries, hospitals and craft rooms, you’ll want to select light bulbs with a CRI rating of at least 90.
  • For most other applications, a CRI rating between 70-89 is perfectly fine. You may even want a bulb with a CRI of around 60, for a more rustic ambience
  • If you select a bulb with a CRI rating of 50 or less, this will be very noticeable to the human eye. Only use this if you’re certain it won’t have an impact on your space (storage cupboards and basic bedrooms).

If You’re A Little Older…

If you’re over the age of 65, choosing lighting with a high CRI rating can be hugely beneficial to your health and well-being. This is because as we age, our eyes find it harder to distinguish between various colours, particularly purples, blues and greens.

This isn’t the same as being colour blind, but it can make once simple tasks that little bit more difficult. In particular, you might find the contrast between words and images is a lot blurrier than it used to be.

If you’re finding yourself struggling to sit down and read a favourite book you once could breeze through, upgrading to higher CRI bulbs in important areas could be the key!

If You Like Getting Crafty…

Artists rely on having an accurate idea of what their creations look like! If you’re a painter, photographer, tailor, knitter, or any other kind of crafter, having your home studio set up with good lighting is key.

This will let you get the best possible understanding of what colours you’re using, and how they go together!

If you’re a budding photographer and you don’t want to beheld to the whims of natural light then it’s especially important that you make sure you have lights with a very good CRI, as these will of course appear on

If You Want A Modern Atmosphere…

One interesting quirk of a high CRI is how it interacts with the colour temperature of your lighting setup. If you’re using lights with a daylight or cool white colour temperature (usually between 4000-5000k and 5000k+ Kelvin ratings, respectively), then a high CRI rating will really help enhance the sharper modern look of your lighting.

Cool white in particular looks amazing in bathrooms and kitchens, where task lighting is often required, meaning it and a good CRI rating pair together perfectly!

If you’re instead looking for a multi-colour set-up, or you want to create a more subdued lighting ambience with a warmer colour temperature (3000k or less) then a high CRI rating can be detrimental.

Got any questions about LED lighting? Our team are on hand to help you with anything you need – simply give us a call on 0116 321 4120, or send an email over to!

Don’t forget that you can keep up to date with all our latest news and products by taking a look at our Facebook and Instagram pages, and a follow on our Twitter feed! You can also subscribe to our YouTube channel.