Propane vs Natural Gas Cost Comparison Calculator

ANALife Services AuthorityNational Calculator Authority›Propane vs Natural Gas Cost Comparison Calculator

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Propane vs Natural Gas Cost Comparison Calculator

Compare the true annual heating cost of propane versus natural gas by accounting for fuel prices, appliance efficiency (AFUE), and your home's heat load.

Propane Price ($/gallon)

Natural Gas Price ($/therm)

Propane Furnace/Boiler Efficiency (AFUE %)

Natural Gas Furnace/Boiler Efficiency (AFUE %)

Annual Heat Load (MMBtu/year)

Typical home: 60–120 MMBtu/year. Check your utility bills or use a Manual J estimate.

Calculate

function proCalc() { var resultDiv = document.getElementById('pro-result');

var propanePrice = parseFloat(document.getElementById('pro-propane-price').value); var ngPrice = parseFloat(document.getElementById('pro-ng-price').value); var propaneAFUE = parseFloat(document.getElementById('pro-propane-afue').value); var ngAFUE = parseFloat(document.getElementById('pro-ng-afue').value); var annualMMBtu = parseFloat(document.getElementById('pro-annual-mmbtu').value);

// --- Validation --- if (isNaN(propanePrice) || propanePrice 100) { resultDiv.innerHTML = 'Propane AFUE must be between 50% and 100%.

'; return; } if (isNaN(ngAFUE) || ngAFUE 100) { resultDiv.innerHTML = 'Natural gas AFUE must be between 50% and 100%.

'; return; } if (isNaN(annualMMBtu) || annualMMBtu 0 ? 'Natural Gas' : (savings 0 ? '#2e7d32' : (savings ' + 'MetricPropaneNatural Gas' + '' + 'Fuel Input Needed (MMBtu/yr)' + fmt(propaneFuelMMBtu,2) + '' + fmt(ngFuelMMBtu,2) + '' + 'Fuel Quantity' + fmt(propaneGallons,1) + ' gal' + fmt(ngTherms,1) + ' therms' + 'Unit Price' + fmtUSD(propanePrice) + '/gal' + fmtUSD(ngPrice) + '/therm' + 'AFUE Efficiency' + fmt(propaneAFUE,1) + '%' + fmt(ngAFUE,1) + '%' + 'Annual Fuel Cost' + fmtUSD(propaneCost) + '' + fmtUSD(ngCost) + '' + 'Cost per MMBtu (useful heat)' + fmtUSD(propaneCostPerMMBtu) + '' + fmtUSD(ngCostPerMMBtu) + '' + '' + '' + '' + winnerMsg + '

' + 'Based on ' + fmt(annualMMBtu,0) + ' MMBtu/year of useful heat required.

'; }

#### Formulas Used

Fuel Input Required (MMBtu/yr): Fuel Input = Annual Heat Load (MMBtu) ÷ (AFUE ÷ 100)

Propane Gallons Required: Gallons = Fuel Input (MMBtu) ÷ 0.0915 MMBtu/gallon (Propane HHV = 91,500 BTU/gallon)

Natural Gas Therms Required: Therms = Fuel Input (MMBtu) ÷ 0.1 MMBtu/therm (1 therm = 100,000 BTU)

Annual Cost: Propane Cost = Gallons × Price ($/gallon) Natural Gas Cost = Therms × Price ($/therm)

Cost per MMBtu of Useful Heat: = Annual Cost ÷ Annual Heat Load (MMBtu)

#### Assumptions & References

More Calculators

References


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