Recessed Light Calculator

The usual question is how many can lights a room needs and how far apart they should go. Recessed Light Calculator answers with a layout instead of a single number. You enter width, length, ceiling height and the height of the surface you care about, such as a kitchen worktop. Then you pick a fixture. The list has preset retrofit and canless models with their lumens and wattage, or you can type in custom specs. Choosing a room type sets a target in foot-candles or lux.

In Auto mode the tool proposes a grid. With its default 12 by 12 ft living room, it suggests six lights in a three-by-two grid, rows 4 ft apart and columns 6 ft apart, for an estimated average of 15.58 fc against a 13.94 fc target.

The results include minimum and maximum levels and a uniformity ratio, which tells you whether the corners will be dim even when the average looks fine. Heatmap, beam coverage and dimension views show the same plan in different ways, and you can switch to presets or a custom grid if Auto's layout doesn't suit the room. You can export a PNG plan, a CSV of fixture coordinates or a print view, and pass the light count to a quick cost estimate.

The site is upfront that these are planning estimates, not measured photometry. Its kitchen examples assume an 8 ft ceiling and 850-lumen fixtures, and note that cabinets, islands and task lighting can change the plan. Separate guides cover kitchens, bathrooms, showers, sloped ceilings, basements and fixture spec sheets.

It's free and needs no account. The homepage says calculations run in your browser and your room inputs aren't sent to a server.