Fire Pit Size Calculator: Diameter, Seating Circle and Clearances

• Seating circle = fire pit diameter + 2 x the gap from rim to chair front
• Chairs = 3.1416 x (seating circle + chair depth) / inches per seat, using about 40 inches per standard chair with elbow room, 34 for compact dining chairs and 46 for Adirondack loungers
• Clear circle = fire pit diameter + 2 x (gap + chair depth + walkway)

Heat output falls off quickly with distance, so the gap is a trade-off: 24 to 30 inches keeps feet warm around a small pit, while large wood fires in 40 inch plus pits push chairs back to 36 inches or more. The calculator starts from the fire pit size typical for your group, then widens the gap only as far as needed to fit everyone.

For wood-burning fire pits, many local codes and fire departments require about 10 to 25 feet from structures, fences, overhanging branches and property lines, and some require more or ban open burning on certain days. Propane and natural gas fire tables generally have smaller clearances set by the manufacturer, but they still need open sky above and distance from siding and umbrellas. Never place a fire pit under a covered patio, pergola, awning or low tree limbs, and set it on a noncombustible surface such as pavers, stone or concrete, not directly on a wood or composite deck unless the manufacturer allows it with the right heat shield. Your local fire code and the manual take priority over any general figure here.

Wood fire pits give more heat and the crackle and smell people buy them for. Smokeless designs such as the Solo Stove Yukon with Stand and the Breeo X Series 24 Corten Steel Smokeless Fire Pit use secondary combustion to reduce, not eliminate, smoke, and dry, seasoned firewood matters more than the pit design. Propane fire tables such as the Endless Summer 44 x 32 in. Rectangular Propane Fire Pit Table light at the turn of a knob, work in many places with wood burning restrictions and double as a table, but they give off far less usable heat and are mostly about ambiance. Portable propane bowls like the Outland Living Firebowl 883 Mega 24 in. Propane Fire Pit split the difference for small groups. See propane vs wood fire pits and the best fire pits.