Does this include heat loss over time?

No. It’s the energy to achieve the temperature rise. Maintaining temp needs additional energy.

What about evaporation or wind?

Not modeled. Use a cover/windbreak to reduce losses.

How do I set efficiency for a heat pump?

Enter COP × 100 (e.g., COP 3 → 300%). Lower it for colder air temps.

Propane vs natural gas?

Rates differ; set energy rate for your fuel. Therm conversion is used for simplicity.

Not here. This focuses on gas/electric heat cost.

construction calculator

Pool Heating Cost Calculator

Estimate energy needed and cost to heat a pool by a chosen temperature rise using gas or electric heat.

Results

BTUs needed: 1,251,000
Energy required (therms or kWh): 15.64
Estimated heating cost: $19

How to use this calculator

Enter pool volume and desired temperature rise.
Choose fuel type and heater efficiency/COP.
Enter your energy rate ($/therm for gas/propane or $/kWh for electric/heat pump).
Review BTUs needed, energy required, and estimated cost.

Inputs explained

Efficiency/COP: Gas heater efficiency % or heat pump COP expressed as a percent (COP 3 ≈ 300%).
Energy rate: $/therm for gas/propane, $/kWh for electric/heat pump.

How it works

BTUs needed = Gallons × 8.34 × ΔT. For gas/propane, therms = BTUs ÷ (100,000 × efficiency). For electric/heat pump, kWh = BTUs ÷ (3,412 × efficiency/COP). Cost = energy units × rate.

Formula

BTUs needed = Gallons × 8.34 × ΔT
Gas/propane therms = BTUs ÷ (100,000 × Efficiency)
Electric/HP kWh = BTUs ÷ (3,412 × Efficiency)
Cost = Energy units × Rate

When to use it

Estimating the cost to warm a pool before a weekend.
Comparing gas heater vs heat pump operating cost.
Budgeting pool heating for a season.

Tips & cautions

Covers and windbreaks reduce heat loss; you may need less energy than this simple estimate.
Heat pump COP drops in cold air; adjust efficiency/COP down for chilly days.
Propane vs natural gas rates vary; set the correct rate for your fuel.
Does not model heat loss over time; this is energy to achieve the temp rise, not maintain it.
Heat pump COP varies with air temp/humidity; efficiency input is user-provided.
No standby/idle losses included.

Worked examples

15k gal, +10°F, gas 80% eff, $1.20/therm

BTUs ≈ 15,000 × 8.34 × 10 = 1,251,000
Therms ≈ 1,251,000 ÷ (100,000 × 0.8) ≈ 15.64
Cost ≈ 15.64 × $1.20 ≈ $18.77

15k gal, +10°F, heat pump COP 3 (300%), $0.15/kWh

BTUs ≈ 1,251,000
kWh ≈ 1,251,000 ÷ (3,412 × 3) ≈ 122
Cost ≈ 122 × $0.15 ≈ $18.30

Deep dive

Estimate pool heating cost by entering pool gallons, temperature rise, fuel type, heater efficiency/COP, and energy rate.

Compare gas vs electric/heat pump costs for raising pool temperature.

FAQs

Does this include heat loss over time?: No. It’s the energy to achieve the temperature rise. Maintaining temp needs additional energy.
What about evaporation or wind?: Not modeled. Use a cover/windbreak to reduce losses.
How do I set efficiency for a heat pump?: Enter COP × 100 (e.g., COP 3 → 300%). Lower it for colder air temps.
Propane vs natural gas?: Rates differ; set energy rate for your fuel. Therm conversion is used for simplicity.
Can I model solar?: Not here. This focuses on gas/electric heat cost.

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Heating energy estimate only. Does not include ongoing heat loss, weather effects, or detailed COP curves. Use manufacturer data for precise planning.