Measure the fire pit and your chairs and say how many sit round it. You get where the chairs go, how big the patio has to be, and how far from the house the fire belongs.
Fire pit seating area
A 15-ft round patio6 chairs 36″ from the fire pit (room for 11) · the fire 25 ft from the house
Quick answer: put the chairs 3 feet from a wood-burning fire pit (2 feet from gas) and leave at least 6 feet of patio all round the pit: a 3-ft fire pit takes a 15-ft round patio and six chairs, a 6-ft one an 18-ft patio. Keep a wood fire 25 ft from the house, the fire code’s distance for a backyard fire.
How to use the fire pit seating calculator
- Measure the fire pit across its outside edge.
- Measure a chair: its width arm to arm and its depth front to back. Adirondack chairs take the most room.
- Say how many seats and what burns: wood in a built pit, wood in a portable fire bowl, or gas.
- Read the patio, where the chairs go and how far from the house the fire stays. Pave this patio takes the size to the paver calculator.
The rules behind the numbers
The chairs
Unilock, the paver maker: “If you have a wood-burning fire pit, chairs or benches should be placed at least 3 feet from the pit”; “If you have a gas fire pit, chairs should be placed at least 2 feet from the pit”; and when the wind picks up, “at least 7 feet”. The calculator sets the chairs side by side on that ring, and moves the ring out when more seats need it.
The patio
Unilock: “plan at least six feet of room on all sides, between the fire pit and the edge of the patio”; for a 3-foot round pit, “a diameter of at least 15 feet total”, room for “four to six chairs”. Belgard: “The patio space around it should be an additional four to six feet on all sides.” Where the chairs’ backs reach farther, they set the patio.
The house
The International Fire Code (2024, §307.4.2): “Recreational fires shall not be conducted within 25 feet (7620 mm) of a structure or combustible material” — a recreational fire being one whose fuel is “3 feet (914 mm) or less in diameter and 2 feet (610 mm) or less in height”. A portable outdoor fireplace, a fire bowl you can move, stays 15 ft away (§307.4.3), except “at one- and two-family dwellings”, where its manual rules. Belgard: “ten feet or more from any structure”. Your city may amend the code: ask the fire department.
Fire pit patio size
Chairs 30″ wide and 33″ deep, 3 ft from a wood fire:
| Fire pit | Chairs it takes | 6 chairs | 8 chairs | 12 chairs |
|---|---|---|---|---|
| 24″ | 10 | 14 ft | 14 ft | 16 ft |
| 36″ | 11 | 15 ft | 15 ft | 16 ft |
| 48″ | 12 | 16 ft | 16 ft | 16 ft |
| 72″ | 15 | 18 ft | 18 ft | 18 ft |
Across a round patio, or the side of a square one.
Four worked examples
A 36″ wood fire pit and six chairs. A 15-ft round patio, the chairs 36″ from the pit, room for 11 of them.
The same pit and twelve chairs. Only 11 fit side by side at 3 ft, so they sit 39″ from the pit, and the patio grows to 16 ft.
A 44″ gas fire pit and eight chairs. The chairs 24″ from it and a 16-ft patio; its distance from the house is in its manual.
A 6-ft fire pit on a square patio. 18 × 18 ft, Unilock’s own example, and 6 ft from the pit to every edge.
Common fire pit mistakes
- Chairs pulled in close. 3 ft from a wood fire, farther in wind.
- A patio sized for the pit, not the chairs. Six feet all round is the least.
- A fire pit by the house or under a tree. The fire code’s 25 ft applies to “a structure or combustible material”.
- A big fire in a big pit. A fire over 3 ft across is not the code’s recreational fire.
Paving it? The free paver patio calculator counts the pavers, gravel and sand for a round or square patio. Planning the rest of the yard? The free 2D planner lays it out to scale.
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Fire pit size questions
What size patio do I need for a fire pit?
The pit plus at least 6 ft all round (Unilock): 15 ft across for a 3-ft pit, 18 ft for a 6-ft one. More chairs than the ring holds make it bigger: twelve 30″ chairs round a 3-ft pit need 16 ft.
How far should chairs be from a fire pit?
At least 3 ft from a wood-burning fire pit and 2 ft from a gas one, and at least 7 ft when it is windy (Unilock).
How far should a fire pit be from the house?
25 ft for a wood fire 3 ft across or less, by the International Fire Code (§307.4.2); 15 ft for a portable fire bowl, except at a one- or two-family home, where its manual rules. Belgard: at least 10 ft from any structure. A gas fire pit: its manual.
What is a good fire pit size?
Belgard: a fire pit “is rarely larger than four or five feet across”. The fire code’s backyard fire is 3 ft across or less, so a pit about 3 ft inside suits it.
How many chairs fit around a fire pit?
With 30″ chairs 3 ft from the pit: 10 round a 24″ pit, 11 round a 36″ one, 12 round a 48″ one. Unilock plans four to six for a 3-ft pit on a 15-ft patio.