Under-Cabinet LED Strips for Kitchens: Worktop Lighting, IP Ratings and Wiring Done Right

Every ceiling downlight layout, however carefully planned, puts a shadow on the worktop directly under the wall units. The cook stands at the counter, their body blocks the ceiling light coming from behind, and the strip of worktop pressed against the cabinets becomes the darkest working surface in the room. That is exactly where you chop, slice, and read recipes. Under-cabinet LED strips fix this and nothing else does. They sit on the underside of the wall units and throw light straight down onto the surface in front of them, with no shadow because the source is below the obstruction.

The catch is timing. The cable run has to be in place before the wall units go up, the strips go in after the units are fitted, and the connection happens at second fix. Every kitchen specification guide lists under-cabinet lighting as a design essential. Yet it is routinely treated as an afterthought, then bolted on as an ugly surface-mounted cable run weeks after the kitchen is finished. Plan it at first fix and it disappears into the cabinetry.

What under-cabinet LED strips are

An under-cabinet LED strip is a flexible printed circuit board carrying surface-mounted LEDs along its length, with a self-adhesive backing tape. Strips are sold on 5m reels and cut to length at marked cut points, typically every 50mm to 100mm. You only cut on the marks: the copper pads at each cut point are where the next section connects or terminates.

The strips do not run on 230V mains. They run on 12V or 24V DC, which means they need a driver (a small transformer, sometimes called a power supply unit) to step the mains voltage down. The driver is the part that connects to the mains side and is usually hidden above the wall units or tucked inside a cabinet. A 2-wire low-voltage cable carries the stepped-down DC from the driver down to the strip itself.

Bare strip stuck straight to a cabinet looks cheap and performs poorly. The proper assembly uses an aluminium channel with a frosted diffuser lens. The channel spreads the light evenly, hides the individual LED hotspots so you see a continuous line rather than a row of dots, dissipates heat, and shields the strip from the cooking vapours that drift up off the hob.

12V versus 24V

The voltage choice comes down to run length. Both formats are sold in the same colour temperatures and the same IP ratings, so this is purely an electrical decision, not an aesthetic one.

12V strips are the common format for kitchens and the default you will find on the shelf at a trade counter. They work cleanly up to roughly 3m to 5m of run at full brightness. Beyond that, voltage drop along the strip means the LEDs at the far end run visibly dimmer than the LEDs nearest the driver.

24V strips push that limit out. They tolerate runs up to around 10m before voltage drop becomes noticeable, because the higher voltage has more headroom to lose along the way.

3-5m

The maximum recommended single run for a 12V strip before end-of-run dimming sets in. A 24V strip extends that to roughly 10m.

For a typical kitchen with 3m to 5m of worktop served by under-cabinet lighting, 12V is the right call. For a large open-plan kitchen with a long island run or a wraparound galley, specify 24V and size the driver to match. The one rule you cannot break: the driver voltage must match the strip voltage. A 12V driver feeding a 24V strip leaves it dim and useless, and a 24V driver feeding a 12V strip will overdrive and destroy it.

IP rating for kitchens

Under-cabinet strips sit directly above the busiest cooking zone in the house. Steam off pans, vapour off the kettle, and fat splatter off the hob all rise straight into them. The rating that describes how well a fitting resists this is its IP rating, where the first digit covers dust and the second covers water.

IP65 (dust-tight and protected against low-pressure water jets) is the minimum sensible specification for any kitchen worktop position. IP44 (splash-resistant) is the absolute floor, and even then it leaves the strip exposed to slow steam ingress that corrodes the LEDs over a couple of years. IP20 strips, which offer no liquid protection at all, have no place in a kitchen.

IP65 strips are usually supplied with a silicone sleeve bonded over the LED tape, or pre-mounted in an IP65-rated aluminium channel that seals the front with a gasketed diffuser.

CCT and colour rendering for task lighting

Two numbers decide how good the light looks: colour temperature (CCT) and colour rendering index (CRI).

CCT is measured in kelvin. For under-cabinet task lighting, 4000K neutral white is the most widely recommended choice. It renders white units honestly, keeps quartz worktops looking clean rather than cream, and shows food in its true colour so you can tell when meat is cooked or whether a vegetable has turned. 3000K warm white suits a traditional kitchen with timber units and stone, but it casts a slight yellow over food and pale surfaces. For the working surface specifically, 4000K is the safer default.

CRI describes how faithfully a light source reproduces colour against natural daylight, on a scale to 100. For any surface where food is prepared, specify CRI 90 or above (often marked "high CRI" or "Ra90"). Budget strips at CRI 80 are perfectly fine for a cupboard or a plinth glow, but under a worktop they make food and finishes look subtly off. The extra few pounds for a Ra90 strip is the easiest quality upgrade in the whole kitchen lighting scheme.

Sizing the driver

The driver has to supply more power than the strip draws, with headroom to spare. Undersize it and it runs hot at full load all day, which shortens its life and risks nuisance shutdowns.

The calculation is simple. Take the strip's power draw per metre, multiply by the run length in metres, then add 20% headroom.

Where the drivers are concealed above the wall units, the power has to get to them, and that is a first-fix job. Provision a 5A fused connection unit (FCU) or a dedicated switched circuit above the cabinet run, positioned over the unit that will house the driver. Get this on the electrical plan before any cable is pulled, because retrofitting it after the units are up means surface trunking and a visible run.

Channels, diffusers and mounting

Bare LED strip on the underside of a cabinet has three problems. The individual LEDs are visible as bright dots when you sit at the table and look up at the run. The self-adhesive backing loses grip over time and the strip sags into a wavy line. And the exposed tape is awkward to wipe clean. An aluminium channel with a frosted polycarbonate diffuser cover solves all three at once.

The strip presses into the channel on its adhesive backing, the diffuser clips or slides over the top to soften the light into a continuous line, and the channel is fixed to the cabinet base with small screws or spring clips. Surface channels, which have a flat base that sits proud of the cabinet, are the standard choice under wall units. Recessed channels, which drop into a slot routed into the cabinet base so the diffuser sits flush, are used on higher-end installations where the channel itself should be invisible.

End caps close off the channel ends for a finished look, and corner connectors let a run turn through 90 degrees without cutting and re-soldering the strip. Where you want a continuous corner with no visible break, use a purpose-made corner channel or feed a short flexible section of strip around the turn.

What to buy

Three components make up a run: the strip, the driver, and the channel. Buy each at the right tier rather than buying everything cheap or everything premium.

Mean Well is the name to look for on the driver. It is the unit professional installers default to because it holds its output and runs cool. The strip is where high CRI earns its place: pay for Ra90 over a worktop and accept CRI 80 only for decorative glow elsewhere. On the channel, the mid tier is usually the sweet spot, because the cheapest extrusions bow.

All three components are stocked by Toolstation, Screwfix, CPC Farnell, Amazon, and LED specialist suppliers such as LEDWarehouse and Fibre Optic FX. Toolstation and Screwfix carry the mainstream IP65 strips, drivers, and channels in-store for same-day collection, which is convenient when you are matching a length on the day of fit.

External resource

Mean Well LED driver selector

Filter Mean Well drivers by output voltage, wattage, and IP rating to match a driver to your strip. Use this to confirm the LPV series rating before buying, rather than trusting a re-seller's listing.

meanwell.com

Smart options

Colour-changing smart strips exist for under-cabinet use. The Philips Hue Gradient Lightstrip Plus (IP67, app control, full colour) and the LIFX Z (Wi-Fi, 16 million colours) both work in this position. Both cost considerably more per metre than a standard white strip.

For a worktop, colour-changing capability is rarely worth the premium. You want clean white light to see what you are doing, not a rainbow. If you genuinely need smart control for scene integration or a gradual morning fade, a cheaper route is to drive a standard high-CRI white strip with a smart relay such as a Shelly module. That keeps the strip itself inexpensive and high quality while still giving you app and scene control.

Common mistakes

Running a 12V strip past 5m on one driver circuit. The far end dims visibly because of voltage drop. Either keep 12V runs under 5m, split a long run across two driver-fed sections injected from both ends, or switch to 24V for the long run.

Using IP20 strip in a kitchen. Cooking steam gets into the unsealed tape and the strip corrodes and fails within one to two years. IP65 is the minimum over any worktop.

Skipping the aluminium channel. Bare strip bonded straight to the cabinet base gives you visible hotspots, a sagging line, and a surface that is awkward to clean. The channel and diffuser are part of the spec, not an optional extra.

Forgetting the power provision at first fix. If there is no FCU or dedicated supply above the wall units when the kitchen goes in, the strips end up fed by a surface-mounted cable run added after the fact. Provision the supply on the electrical plan before first fix.

Sizing the driver exactly at the load. A driver run flat out at 100% load all day overheats and fails early. Always specify a driver rated about 20% above the calculated strip load.

Where you'll need this

• Electrical layout planning, agree the under-cabinet supply position and switching before any cable is run
• Kitchen electrical provisions, the FCU or dedicated circuit above the wall units is a first-fix cable run
• Kitchen installation, strips, channels, and drivers are fitted and connected once the units are in