How Many Under Cabinet Lights Do You Need Based On Space Size?

Cabinet runs in a real kitchen are rarely uniform, and the wall above a counter is frequently broken up by range hoods, windows, and corners. Working out how many under-cabinet lights you need starts with treating each of those segments separately rather than measuring the room. A single figure for the whole kitchen almost always produces gaps at one end and overlap at the other. Fixture count follows from the lit run, the coverage target, and the brightness the counter calls for. Let's work through it.

Measure The Lit Run, Not The Whole Room

Segments of cabinetry, taken one at a time, give the only figures worth ordering from. Record the width of each upper cabinet or continuous bank of cabinets in inches, and note where the run breaks for a hood, a window, an open shelf, or a corner. Total kitchen square footage tells you nothing useful here, since the light only ever falls on the counter beneath a cabinet. Depth of the cabinet and its height above the counter belong in the same notes, as both affect how far the beam spreads. Five minutes with a tape measure replaces a great deal of guesswork at the ordering stage.

The Coverage Target That Sets Your Count

Fixtures spanning roughly two-thirds of each cabinet width produce a band that reads as continuous rather than a row of bright patches. Multiply the width of the run in inches by 0.66, and the result is the fixture length to aim for along that segment. A 36-inch cabinet therefore wants around 24 inches of fixture. When that number falls between two available sizes, you can go a few inches under or over without much difference in the finished look, and a 22-inch bar sits close enough to the target.. Wider banks usually take two linked bars, so a 60 inch run wants about 40 inches and pairs a 22 with a 14. Rounding down slightly is safer than overshooting and running the fixture past the cabinet edge.

Brightness A Working Counter Calls For

Length alone does not settle the question, since a prep counter and a display shelf need very different output. Around 350 to 400 lumens per linear foot suits a working counter where chopping and reading recipes happen, while 200 to 250 lumens per foot is ample for a bar or open shelving. Fixture output tracks length fairly closely, with a 22 inch bar producing 750 lumens and a 28 inch bar producing 900. Dark counters and dark cabinets absorb light, so a run over walnut or slate benefits from the higher end of that range. Dimming lets you pull the level back for evenings without giving up daytime brightness.

Matching Fixture Lengths To Cabinet Widths

Common cabinetry arrives in a predictable set of widths, and the available bar lengths map onto them neatly. Use the pairings below once each run is measured. These numbers suit general lighting rather than task lighting, so plan on more output per foot if the counter is your main prep area.

Longer banks combine two linked fixtures rather than stretching a single unit beyond its reach.

Small, Medium, And Large Kitchen Examples

Treat each cabinet run on its own when you work through these steps. A run does not affect the one beside it, so you can size each segment separately and add them up at the end.

Example 1: A 36 inch run

Step 1: Find the target length. Multiply 36 by 0.66, which gives about 24 inches. That is the length to aim for along the run.

Step 2: Find the brightness needed. General lighting calls for roughly 50 lumens per foot, so a 3 foot run needs about 150 lumens. For task lighting, aim closer to 100 lumens per foot, which puts the same run near 300 lumens.

Step 3: Pick a fixture size. The 24 inch target falls between two common sizes. You can go a few inches under or over without much change in the finished look, so a 22 inch bar at about 800 lumens works here and leaves plenty of headroom for task work.

Example 2: A 48 inch run

Step 1: Find the target length. Multiply 48 by 0.66, which gives about 32 inches.

Step 2: Find the brightness needed. At 50 lumens per foot, a 4 foot run needs about 200 lumens for general lighting. At 100 lumens per foot for task work, it needs about 400.

Step 3: Pick a fixture size. The 32 inch target sits between a 28 and a 33 inch bar. Either works. The 33 inch bar lands closer to the target and gives more output, so it is the safer pick if the counter sees heavy use.

One Long Bar Or Several Short Ones?

A single longer bar usually beats several short ones covering the same width. Three 8 inch bars add up to 24 inches, but they leave two gaps where shadows can form and the light reads as three patches instead of one band. Chaining also adds joints and cables inside the cabinet. One 24 inch bar spreads light evenly across the whole span and keeps the install simple.

One thing to note: If the design team can build simple diagrams, these three examples would be much easier to follow as illustrations. A single image showing the 0.66 multiplier on a 36 inch run, a second showing the flex rule when the target falls between sizes, and a third comparing three short bars against one long bar would do most of the teaching. Worth flagging to them.

Size Your Run With NuWatt

Counting fixtures accurately comes down to measuring each cabinet run on its own, aiming at two-thirds coverage, and checking the lumen total against the work that counter does. Our under-cabinet line covers 8, 11, 14, 22, 28, 33, and 42-inch bars rated from 180 to 1250 lumens, which gives you a size for almost any segment. Every bar is linkable, so two units can be chained to fill a width one cannot, and the whole run answers to a single wall switch. All models carry 90 CRI, five selectable color temperatures, dimming, and a five year warranty, and every order ships free with no minimum.

Browse our collection today and get in touch if you want a hand sizing the run for your kitchen.