Cannabis Grow Room Layout Calculator

The per-plant footprint the calculator assigns to each training method spans a 6x range — about 1 sq ft per plant for SOG versus 4 sq ft for LST/SCROG and 6 sq ft for mainlining — because SOG relies on packing many small, quickly-flowered plants tightly together while SCROG and mainlining deliberately spread a smaller number of plants into wide, trained canopies. Since max plant count is just canopy area divided by that footprint, the same 15x15 room can hold roughly six times as many SOG plants as mainlined plants.

The walkway percentage is applied directly to your total floor area (length × width) before the remainder becomes canopy area available for plants — so a 25% walkway allowance on a 300 sq ft room removes 75 sq ft up front, leaving only 225 sq ft to divide by your per-plant footprint. Growers tight on space should weigh whether the default 25% is more clearance than their actual room and equipment layout requires, since every point of walkway percentage directly reduces usable canopy.

This calculator's fixture estimate is a simple area-coverage figure — canopy square footage divided by 16 (assuming standard 4×4-foot fixture coverage) — with no adjustment for target PPFD, fixture type, or hang height. A dedicated lighting calculator that accounts for those factors may recommend a different fixture count for the same canopy area, so treat this number as a rough space-planning cross-check rather than a final lighting design.

Max plant count is derived purely from total canopy area divided by per-plant footprint, while number of rows and plants-per-row are calculated separately from your entered row spacing and the square root of the per-plant footprint, without walkway deduction applied the same way. These two figures are meant as independent planning cross-checks on the same room, not a strict row-by-row breakdown that multiplies out to exactly the max plant count.