basic

Propane-Tank Burn Time from BTU Rating Calculator

hours = (gallons × 91 500) / appliance_BTU/h.

Compute the burn time of a propane tank given its size in gallons and the appliance's BTU/hr rating. 1 US gallon of liquid propane contains ~91 500 BTU. A 20-lb 'BBQ tank' (4.7 gal) at a 30 000 BTU/h grill = 14.3 h; a 100-lb tank (23.6 gal) at 75 000 BTU/h heater = 28.8 h.

Marcus Laurent By Marcus Laurent
Published Last reviewed 1 min read

Inputs

gal
BTU/h

Results

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How to use this calculator

  1. Fill in the inputs above using the units you already have.
  2. Values update automatically as you type — no submit button needed.
  3. Hover any result row for the underlying formula and intermediate values.

Formula

hours = (gallons · 91 500) / BTU/h.

In depth

Compute the burn time of a propane tank given its size in gallons and the appliance's BTU/hr rating. 1 US gallon of liquid propane contains ~91 500 BTU. A 20-lb 'BBQ tank' (4.7 gal) at a 30 000 BTU/h grill = 14.3 h; a 100-lb tank (23.6 gal) at 75 000 BTU/h heater = 28.8 h.