Gas vs Heat Pump Heating Cost Calculator
Compare annual heating costs for gas boiler and heat pump with your own prices, efficiency, and maintenance assumptions.
Last updated: How it is calculated
Heating Inputs
Almost nobody knows their annual heat demand in kilowatt hours. Floor area and roughly when the building went up are enough for a first answer.
Estimated heat demand: 15,750 kWh
From 140 m² at 125 kWh/m² a year of consumed energy for a building of that age, times a boiler efficiency of 90 % to get the heat actually delivered. Source: Heizspiegel 2025/2026, co2online. The figure already includes hot water.
Gas boiler assumptions
Heat pump assumptions
Heating Cost Results
Gas annual cost
$1,401.00
Heat pump annual cost
$1,087.59
Recommendation
Heat pump is cheaper
Annual difference (gas - heat pump): $313.41
Estimated payback: 28.7 years
Detailed comparison
Tip: revisit energy prices annually to keep this comparison realistic.
How it is calculated
Formula
Estimating heat demand = floor area × the consumption benchmark for the build year × boiler efficiency (the benchmark is end energy consumed, hot water included, so it is multiplied rather than divided) Gas: energy input = heat demand ÷ boiler efficiency; cost = energy input × gas price + servicing Heat pump: electricity = heat demand ÷ seasonal performance factor; cost = electricity × power price + servicing Difference = gas cost − heat pump cost
What this calculator does not account for
- The seasonal performance factor depends heavily on insulation, flow temperature and radiators — it is the single biggest lever here.
- Purchase costs enter through the single "heat pump extra cost" field, which alone drives the payback period. Subtract any subsidies from it yourself.
- Special heat-pump electricity tariffs and dynamic pricing are not modelled.
- Carbon pricing and future energy price rises are not projected.
About This Calculator
This heating comparison calculator estimates annual costs for gas boiler versus heat pump based on your own heat demand, energy prices, efficiency assumptions, and maintenance costs. It also estimates payback for additional heat pump investment.
How to Use This Calculator
- 1
Enter your annual heat demand in kWh (from bills or energy certificate).
- 2
Add gas assumptions: price per kWh, boiler efficiency, and annual maintenance.
- 3
Add heat pump assumptions: electricity price, seasonal COP (JAZ), and annual maintenance.
- 4
Optionally enter extra upfront investment and review annual difference and payback.
Why Use This Calculator
Clear Annual Cost View
See both systems on a comparable annual basis using your own demand and tariff assumptions.
Payback Estimate
Estimate how many years it may take for lower running costs to recover extra upfront investment.
Planning-Friendly Inputs
Use values from your existing documents without needing weather APIs or external datasets.
Frequently Asked Questions
Use a realistic seasonal value from installer documents or measured operation. Overly optimistic COP assumptions can understate cost.
You can use historical heating bills, energy certificate data, or building energy audit estimates for annual demand input.
No. Enter your net extra upfront cost after any grant or rebate so payback reflects your real out-of-pocket investment.
Maintenance affects total operating cost and can materially change the comparison, especially over multiple years.
Yes. If gas or electricity prices move significantly, rerun the calculator with updated values to keep the comparison current.
No. This tool focuses on annual operating comparison plus optional payback. Full lifecycle analysis needs additional capital and replacement assumptions.
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Disclaimer: This calculator provides estimates for planning purposes only. Actual costs may vary based on your circumstances, location, and market conditions. Not financial advice. See our Terms of Service for full disclaimers.