If you want to know how warm or cold the light of your new LED lamp will be you should check the Kelvin value (K) printed on the packaging – and often on the lamp itself as well. Lamps with the lowest Kelvin value emit the warmest and most relaxing light colour; lamps with the highest Kelvin value produce the harshest and coldest white light. Here’s a guide:
1,800 K warm glow like candlelight
2,200 K warm white light like a light bulb
2,700 K soft white light but less cozy than a light bulb
3,000 K bright white light, slightly more yellow than a classic fluorescent lamp
4,000 K cold white light like that of a classic fluorescent lamp
Unfortunately even the cosiest LEDs eventually peter out, albeit after an average of 50,000 hours. And then you can discard them properly by handing them in at the container park or your local Recyclepoint.