How many BTUs does your patio need?

As a baseline, plan for about 30 BTUs per square foot of the area people actually use. A small covered patio of 150 sq ft needs roughly 4,500 BTUs, while a 400 sq ft open space can need 12,000 or more once you account for wind and cold. Open and breezy spaces lose heat fast, so they need more output than a sheltered, covered area of the same size. The calculator above adjusts for all of that automatically.

Size to the active seating zone, not the whole patio. Measure where people gather — dining and lounge areas — then match a heater's rated coverage to it. If one unit can't cover the space, two smaller heaters placed over each seating area beat one oversized heater in the corner. Our calculator recommends the exact model and quantity for your dimensions.

Those common freestanding ratings work well for medium-to-large open areas of roughly 150 to 215 sq ft. Raw BTUs aren't the whole story: a well-placed, well-built heater delivers more usable warmth than a higher-BTU unit aimed at dead space. The premium Bromic heaters we carry focus heat where people sit rather than scattering it.

Electric radiant heaters shine in covered or semi-enclosed spaces with manageable wind: they direct heat right where people sit, look clean, and need no tank. Gas heaters deliver the brute output that open, breezy patios demand. The calculator recommends whichever fits your conditions.

Yes — covered patios are ideal for radiant heaters and actually need less output because the roof holds warmth in. Just respect the heater's minimum clearance to the ceiling. A solid roof performs better than a slatted pergola, which behaves closer to an open space in wind.

Follow each model's listed clearances to walls, ceilings, and combustible surfaces — they vary by heater and mount type. Mounted electric and gas units list both minimum mounting height and side clearances on their spec sheets. When in doubt, ask us and we'll confirm the safe layout for your exact heater.