A CCT LED strip carries two rows of white LEDs, one warm and one cool, and a controller blends them to whatever shade of white you want. Turn it towards warm for a soft evening glow, towards cool for bright task light over the worktop, and the same strip does both jobs without rewiring.
You will also see it sold as tunable white or dual white. Compared with a single-colour strip, it needs a third wire, a two-channel controller and a driver sized for both channels running together.
CCT stands for correlated colour temperature, measured in kelvin. On the strip, warm-white chips (typically around 2700 K) and cool-white chips (around 6500 K) alternate or share one package. Both share a common positive, and each has its own negative channel. The controller dims each channel independently, so the mix moves smoothly along the scale rather than jumping between fixed settings.
That is the key difference from fittings marked 3CCT, such as many downlights, where a small switch on the driver lets the installer pick one of three whites before fitting. A strip with a CCT controller can be changed any time from a remote, a wall plate or a phone.
| Setting | Kelvin | Where it suits |
|---|---|---|
| Candlelight / warm dim | 1800–2200 K | late evenings, bedrooms (only on extended-range strips) |
| Warm white | 2700–3000 K | living room coving, dining, bedrooms |
| Neutral white | 3500–4500 K | kitchen worktops, utility rooms, wardrobes |
| Cool white | 5000–6500 K | home office, garage workbench, make-up mirror |
Most strips span 2700–6500 K or 3000–6000 K; a few start at 2200 K. A wide range gives you more mood, though the middle of the scale can look a touch less crisp than either end.
A standard single-channel dimmer cannot balance two whites, so you need a CCT (dual-white) controller between the driver and the strip. Options range from RF remotes, which work through cabinet doors, to wall-mounted touch or rotary panels, Wi-Fi and Bluetooth receivers with an app, and Zigbee units for an existing smart-home hub. Larger installations may use DALI DT8. Check the maximum current per channel and add an amplifier on long runs rather than overloading one controller.
Classic spots in a UK home are under kitchen wall units, along plinths, in coving or a recessed ceiling detail, behind a bathroom mirror and around a home-office desk. Mount the strip in an aluminium channel: it pulls heat away from the LEDs, which is what shortens their life. Use three-core cable, keep strips from one batch in a continuous run so the whites match, and power long lengths from both ends. The 230 V side of the driver should be connected by a qualified electrician to BS 7671, and in bathrooms the zone rules decide where the driver and strip may go. Leave the driver somewhere you can reach later.
The lumen figure on a CCT strip's spec sheet is normally measured with both channels at full. Slide the controller all the way to warm or all the way to cool and only half the LEDs are working, so expect roughly half that output. For a kitchen worktop lit at a neutral setting that rarely matters. If you want plenty of light at 2700 K in a living room, choose a strip with more lumens per metre or run two strips side by side in a wider channel.
Controllers also behave differently in the middle of the scale. Some hold overall brightness steady as you shift the colour; others simply add the two channels, so the mid-point looks brighter than either end. Try the controller with a short length on the bench before anything goes up, and wipe the diffuser with a dry cloth now and then rather than using solvents on a silicone-coated strip.
It describes a fitting with a selector offering three fixed whites, often 3000 K, 4000 K and 6000 K, chosen once during installation. A CCT strip is continuously adjustable instead.
No. CCT is the colour of the light, in kelvin; lumens measure how much light there is. A strip can be very bright at 2700 K or dim at 6500 K.
The voltage is usually printed on the strip near the solder pads or on the reel label. Cut intervals help too: 24 V strips are often cut in longer sections than 12 V ones of the same density. If in doubt, check the driver output rather than guessing.
Only across the marked copper pads, usually every 2.5–10 cm. Cutting anywhere else kills that section.
Three: common positive, warm white and cool white. RGB uses four and RGB+CCT six.
Not to a CCT strip. If you want colour as well as tunable white, look at RGB LED strip lights in an RGB+CCT version from the start.
Still weighing tunable white against a fixed colour? More on strip types, power and fitting in general: LED strip lights.
