Recessed Light Calculator is a free, browser-based planning tool for rectangular rooms. Enter your room dimensions and assumptions to estimate fixture count, spacing and wall distance, then compare 2D layouts. It needs no account, runs its calculations in the browser and requires JavaScript.
Export the plan as a PNG or the coordinates as a CSV. The site also links a separate installation cost calculator and lighting guides. The page says its outputs are planning estimates, not photometry or code compliance, so use it for early planning and confirm a final installation with a qualified professional. It is web only.
The goal is to make early recessed-light planning easier to understand: turn a few rectangular-room inputs into a transparent starting point for fixture counts and spacing.