01
The purpose
What does this calculator estimate?
Compare the yearly running cost of gas, propane, electric, and heat pump heaters side by side.
Heating & Energy · D8
Pool Heater Cost Comparison: Gas vs Electric vs Heat Pump
Compare the yearly running cost of gas, propane, electric, and heat pump heaters side by side.
Measure the inputsNatural gas usually wins on cost where a gas line is available.
Read the full resultHeat pumps rival or beat gas in mild climates thanks to COP of 4–5.5.
Check the boundaryPropane is convenient off-grid but the priciest common fuel per BTU.
Useful forHeating & EnergyPlanningComparisonVerification
Live calculation
Comparison inputs
✓ Checked May 2026
Enter annual heating demand and your fuel rates.
Best comparison
—
Enter annual heating demand to compare all four heater types.
Enter the known values. Let the engine handle the calculation.
✓ Formula checked↻ Live result○ No account needed
Planning estimate only. Confirm product labels, equipment specifications, qualified-professional advice and local requirements before acting.
The result, explained
Use the Pool Heater Cost Comparison: Gas vs Electric vs Heat Pump result with context.
Compare the yearly running cost of gas, propane, electric, and heat pump heaters side by side.
02
The tool
What information does it use?
- Annual heating demand: Total BTU per year (from heat-loss × season).
- Natural gas rate: $ per therm.
- Propane rate: $ per gallon.
- Electric rate: $ per kWh.
- Heat pump COP: Typical 4–5.5 in mild climates.
03
The method
How to use this calculator
- Annual heating demandTotal BTU per year (from heat-loss × season).
- Natural gas rate$ per therm.
- Propane rate$ per gallon.
- Electric rate$ per kWh.
- Heat pump COPTypical 4–5.5 in mild climates.
04
The relationship
The formula in plain English
Each fuel: annual cost = (BTU/yr ÷ efficiency or COP) → fuel units × rate
Gas 85%, electric resistance 99%, heat pump uses COP. Lowest cost is ranked first.05
Worked through
A worked example: 5,000,000 BTU/yr demand, comparing all four
- Gas: 5M ÷ 0.85 ÷ 100,000 = 58.8 therms × $1.50 = $88
- Heat pump: 5M ÷ 5 ÷ 3412 = 293 kWh × $0.14 = $41
- Heat pump wins; resistance ($207) loses
| Heater type | Efficiency / COP | Fuel / year | Annual cost* |
|---|---|---|---|
| Natural gas | 85% | 58.8 therms | ~$88 |
| Heat pump | COP 5.0 | 293 kWh | ~$41 |
| Propane | 85% | 64.3 gal | ~$225 |
| Electric resistance | 99% | 1,480 kWh | ~$207 |
06
Why it matters
How the result supports the next decision
Natural gas usually wins on cost where a gas line is available.
Heat pumps rival or beat gas in mild climates thanks to COP of 4–5.5.
07
Good inputs
Improve the estimate before relying on it
- Natural gas usually wins on cost where a gas line is available.
- Heat pumps rival or beat gas in mild climates thanks to COP of 4–5.5.
- Propane is convenient off-grid but the priciest common fuel per BTU.
- Electric resistance is cheapest to install but brutal to run — avoid for whole pools.
- Factor install cost and lifespan, not just running cost, for the true comparison.
08
The boundary
How to interpret the result
Measurements, equipment specifications, site conditions and local requirements can change the practical result.
The engine reports invalid inputs and safety warnings beside the result. Resolve those messages before using the estimate.
09
Before acting
What should override this estimate?
- Measured site conditions and current test results
- Product labels and manufacturer specifications
- Qualified-professional advice and applicable local codes
10
Common questions
Frequently asked questions
What is the cheapest pool heater to run?
Where a natural gas line is available, gas is usually cheapest to run, closely matched or beaten by a heat pump in mild climates because of its high COP. Propane costs considerably more per BTU, and electric resistance heating is the most expensive of all to operate despite being the cheapest to install.
Is a heat pump or gas heater better?
It depends on climate and rates. Heat pumps are far cheaper to run in mild, warm conditions and have low emissions, but they heat slowly and cost more upfront. Gas heaters heat fast and work in any weather but cost more per BTU to run. Many owners in cold-snap climates keep gas for speed.
How much does it cost to run each heater type per year?
It scales with your annual heating demand and rates. For the same delivered heat, gas and heat pumps typically land lowest, propane higher, and electric resistance highest — often several times the cost of gas. The calculator ranks all four for your specific demand and local prices.
Why is electric resistance heating so expensive?
Because it converts electricity directly to heat at roughly one-to-one, with no multiplication. A heat pump using the same electricity moves four to five times as much heat thanks to its COP. So for the identical warmth, resistance heating uses several times more electricity, making it the costliest option to run.
Should I compare install cost or running cost?
Both. Electric resistance is cheap to install but expensive to run; heat pumps and gas cost more upfront but far less per year. The right choice weighs the total cost of ownership over the heater's lifespan — purchase plus install plus years of fuel — against how often you actually heat.
Gas vs heat pump pool heater — which is cheaper?
Heat pumps usually win on running cost in mild climates; gas wins on speed and in cold weather.
How much does it cost to run a pool heat pump per year?
Often a few hundred dollars in a mild climate — far less than electric resistance, and competitive with gas.
Is propane expensive for pool heating?
Yes — propane costs more per BTU than natural gas, though it's common where no gas line exists.
Primary sources
Use the result with current guidance.
These official references support safe planning context. Product labels, local requirements and qualified-professional advice take priority over a general calculator estimate.