Last updated: 19 August 2026
What does 2700K mean?
2700K is "warm white" — the cosy, slightly yellow glow you'd recognise from old incandescent bulbs. The "K" stands for Kelvin, the unit for a bulb's colour temperature: how warm or cool its light looks.
The Kelvin scale in brief
Colour temperature runs from warm to cool as the Kelvin number rises — which is a little counterintuitive. Low numbers (around 2200–3000K) look warm and yellow; high numbers (5000–6500K) look cool and blue-white. 2700K sits firmly at the warm end.
| Kelvin | Look |
|---|---|
| 2700K | Warm white (like old incandescent) |
| 3000K | Soft warm white |
| 4000K | Neutral white |
| 5000–6500K | Cool white to daylight |
Why 2700K specifically?
Old incandescent bulbs glowed at roughly 2700K, so bulb makers use that figure as the "traditional household" warm white. If you're replacing incandescent bulbs and want the same familiar feel, 2700K is the closest match.
Where 2700K works best
It suits the rooms you relax in: bedrooms, living rooms, dining rooms, hallways and table lamps. In kitchens, bathrooms and workspaces, many people prefer a slightly cooler 3000–4000K for crisper task light — though that's a matter of taste.
Related: Warm vs cool white · Find the right LED bulb