🔥 Fire Pit Gas Line Size Calculator
Find the correct pipe diameter for your BTU load & run length — natural gas or propane
| Pipe Size | 10 ft Run | 20 ft Run | 30 ft Run | 50 ft Run | 75 ft Run | 100 ft Run |
|---|---|---|---|---|---|---|
| 3/8 in | 72,000 | 50,000 | 40,000 | 31,000 | 25,000 | 22,000 |
| 1/2 in | 175,000 | 120,000 | 97,000 | 78,000 | 63,000 | 52,000 |
| 3/4 in | 360,000 | 250,000 | 200,000 | 160,000 | 130,000 | 108,000 |
| 1 in | 678,000 | 466,000 | 375,000 | 304,000 | 247,000 | 204,000 |
| 1-1/4 in | 1,390,000 | 950,000 | 770,000 | 620,000 | 500,000 | 415,000 |
| 1-1/2 in | 2,090,000 | 1,430,000 | 1,150,000 | 920,000 | 750,000 | 620,000 |
| 2 in | 3,950,000 | 2,710,000 | 2,200,000 | 1,740,000 | 1,420,000 | 1,170,000 |
| Pipe Size | 10 ft Run | 20 ft Run | 30 ft Run | 50 ft Run | 75 ft Run | 100 ft Run |
|---|---|---|---|---|---|---|
| 3/8 in | 59,000 | 41,000 | 33,000 | 25,000 | 20,000 | 18,000 |
| 1/2 in | 143,000 | 98,000 | 79,000 | 64,000 | 52,000 | 43,000 |
| 3/4 in | 294,000 | 204,000 | 163,000 | 131,000 | 106,000 | 88,000 |
| 1 in | 554,000 | 381,000 | 306,000 | 248,000 | 202,000 | 167,000 |
| 1-1/4 in | 1,136,000 | 777,000 | 629,000 | 507,000 | 409,000 | 339,000 |
| 1-1/2 in | 1,709,000 | 1,169,000 | 940,000 | 752,000 | 613,000 | 507,000 |
| Fitting Type | 1/2 in equiv. ft | 3/4 in equiv. ft | 1 in equiv. ft | 1-1/4 in equiv. ft |
|---|---|---|---|---|
| 90° Elbow | 2.0 | 2.5 | 3.0 | 4.0 |
| 45° Elbow | 1.0 | 1.5 | 2.0 | 2.5 |
| Tee (straight) | 1.5 | 2.0 | 2.5 | 3.0 |
| Tee (branch) | 3.5 | 4.5 | 5.5 | 7.0 |
| Ball Valve (full port) | 0.5 | 0.5 | 0.7 | 1.0 |
| Union / Coupling | 0.3 | 0.4 | 0.5 | 0.6 |
| Project Type | Typical BTU | Typical Run | Gas Type | Min Pipe Size |
|---|---|---|---|---|
| Tabletop Fire Bowl | 30,000–50,000 | 10–20 ft | NG or LP | 3/8 in |
| Small Patio Fire Pit | 50,000–80,000 | 15–30 ft | NG or LP | 1/2 in |
| Standard Fire Pit | 80,000–150,000 | 20–50 ft | NG or LP | 3/4 in |
| Large Backyard Fire Pit | 150,000–200,000 | 50–75 ft | NG | 3/4 in |
| Outdoor Kitchen + Fire | 200,000–300,000 | 50–100 ft | NG | 1 in |
| Commercial Fire Feature | 300,000–500,000 | 50–100 ft | NG | 1-1/4 in |
| Multi-Burner System | 500,000+ | 75–150 ft | NG | 1-1/2 in |
Choosing a Fire Pit for your backyard can make the outdoor garden nicer, however the setup of the Gas Line Size requires attention and care. One of the main choices is deciding between natural gas or propane. With natural gas you must run a permanent line, so no need to always buy propane tanks.
For propane one can place a regular tank hidden nearby which helps more freely choose the spot.
Pick the Right Gas Line Size for Your Backyard Fire Pit
The size of the tubes matters a lot. For home Fire Pit setups people tend to use tubes with half-inch or three-quarter-inch width. A tube of half inch works for Fire Pit setups up to around 100,000 BTU.
If the Gas Line Size is too narrow it limits the flow of the fuel and results in weak tiny flames. Every burner of a Fire Pit has its BTU rating, while the line limits the amount of BTU that it can carry. To figure out the right Gas Line Size, one needs to know the total length of the gas line and the BTU needs of the Fire Pit.
For underground lines people usually use tubes from high-density plastic, which is approved for natural gas. Flexible ridged stainless steel tubing normally must be laid in a pipe if it is bureid directly. Tubes from PVC work for gas at low pressure, when the regulator is beside the tank.
Before digging any hole, it is best to call 811 so that they mark the lines, it is free and saves money against problems.
Regulators play a big role. When one runs propane from a tank too a buried line, the cost for such work with two regulators and plastic tube buried in eighteen inches of depth ranges between 750 and 1,200 dollars. This amount includes the fittings, the tube and the regulators at the tank and at the Fire Pit.
Hire a professional to install the Gas Line Size to protect against dangerous leaks and ensure that everything matches the standards. Plumbers usually are not ready to work outside on gas supply for a Fire Pit, especially if it connects to the home line. Better to choose a contractor that specializes in gas work.
Fire Pit setups come in many kinds of shapes and styles, like round, rectangular, square or even six-sided models. The materials range from concrete and metal to stone. Gas Fire Pit setups cost more than wood-burning versions, but they come in various prices.
A real benefit of gas Fire Pit setups is that one can use them during burn bans. In many areas wood fires are banned because of fire risk and ashes, but gas flames usually stay allowed. A twenty-pound propane bottle stores around 400,000 BTU, so for a Fire Pit at medium level of around 35,000 BTU it gives almost eleven hours ofburn time.
That is enough for some long evenings around the fire.
