175–250 lumens per linear foot of worktop for task lighting. A 6 ft run of cabinets wants roughly 1,050–1,500 lumens in total.
Unlike room lighting, this is specified per foot rather than per square foot, because the surface is a strip rather than an area.
| Run length | Task lighting | Accent only |
|---|---|---|
| 3 ft | 525–750 lm | 180–300 lm |
| 4 ft | 700–1,000 lm | 240–400 lm |
| 6 ft | 1,050–1,500 lm | 360–600 lm |
| 8 ft | 1,400–2,000 lm | 480–800 lm |
| 10 ft | 1,750–2,500 lm | 600–1,000 lm |
The accent column is for a run that exists to make the kitchen look good at night rather than to chop vegetables under. Around a third of task level.
Position matters more than output
Mount the strip at the front edge of the cabinet underside, not at the back against the wall.
At the front, light falls across the whole depth of the worktop, and the cabinet itself hides the strip from anyone standing in the room.
At the back, three things go wrong at once: the front half of the worktop stays dim, light bounces off the vertical splashback into your eyes, and a glossy worktop shows a clear reflection of the strip.
If the cabinet has no lip to hide the fitting, use a channel with a diffuser. A bare strip of LEDs reflected in a polished granite worktop is a row of visible dots.
Continuous, not spotty
Use a continuous strip or a channel, not puck lights. Pucks put down a row of overlapping circles, and on a reflective worktop they produce a row of bright hot spots with dim gaps.
If pucks are already installed, spacing them at roughly 12 inches and fitting frosted lenses gets most of the way to a strip.
Color temperature: cooler than the room
This is the one place in a kitchen where a cooler color temperature belongs even if the room is warm.
Under-cabinet: 3500–4000K. Cooler light resolves detail and edge definition better, which matters when what you are looking at is a knife against a chopping board.
Room lighting: 2700–3000K if the kitchen has warm finishes.
Normally mixing color temperatures within one sightline looks like a fault — but the exception is a source you never see directly. You look at the worktop, not the strip, so the room keeps its warm character while the work surface gets the crisper light. The reasoning is in 3000K or 4000K in a kitchen.
Color rendering matters here
You are judging food under this light: whether meat is cooked through, whether a sauce has caught, whether the herbs are still good.
CRI 90 or above for under-cabinet lighting, and pay attention to R9 — the deep red value that most CRI 80 products score badly on and that food depends on more than any other color. See what a good CRI is.
Wire it separately
Under-cabinet lighting on its own switch is worth the extra cable. It becomes the low-level evening light for the whole kitchen — enough to make tea by, not enough to wake anyone up — and that turns out to be the setting it spends most of its life on.
Put it on a dimmer as well if you can. Low-voltage LED strip and mains dimmers do not always cooperate, so check what the driver supports before buying; the failure modes are in dimmer compatibility with LED.
The rest of the kitchen
Under-cabinet lighting is a task layer and does not count toward the room's general lighting. Work that out separately from how many lumens a kitchen needs, or get the figure for your dimensions from the kitchen lighting calculator.