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What does the Heating system cost comparison calculate?
Which heating option costs less under your rates? This calculator uses annual heat needed, system a efficiency, system a energy price, system b efficiency / cop, and system b energy price to estimate annual heating comparison immediately in your browser.
With the values currently entered, the result is System B — has the lower energy cost. It also shows system a / year, system b / year, and difference / year.
How to use the Heating system cost comparison
- Replace the example values with your own numbers.
- Review the result and supporting figures as they update automatically.
- Check the formula and assumptions before using the estimate for a decision.
Inputs used
- Annual heat needed — entered in kWh heat
- System A efficiency — entered in %
- System A energy price — entered in / kWh
- System B efficiency / COP — entered in %
- System B energy price — entered in / kWh
Heating system cost comparison formula
Heat demand ÷ system efficiency × energy price
Assumptions
- Annual heat demand is the same for both systems.
- Maintenance and installation costs are excluded.
Verify the inputs
Authoritative sources
These sources explain the definitions, factors, or rules behind this tool. Their geographic scope is shown because an official source for one country is not automatically valid somewhere else.
Sources do not endorse Calculum. Check the source date, scope, and your own documents before making a financial, tax, insurance, or reporting decision.
Practical guide
Heating system cost comparison example and edge cases
Which heating option costs less under your rates? Let's use a concrete example, then look at the assumptions that can move the answer.
Example: A practical heating system cost comparison scenario
For this example, use annual heat needed of 12,000 kWh heat, system a efficiency of 90 %, system a energy price of 0.12 / kWh, system b efficiency / cop of 320 %, and system b energy price of 0.32 / kWh. These are starting values, so replace them with numbers that match your situation.
- Annual heat needed
- 12,000 kWh heat
- System A efficiency
- 90 %
- System A energy price
- 0.12 / kWh
- System B efficiency / COP
- 320 %
- System B energy price
- 0.32 / kWh
Calculated resultSystem Bhas the lower energy cost
Start with has the lower energy cost. Then check system a / year, system b / year, and difference / year to understand what sits behind the main result.
Example results use the default display profile. The calculator above follows your selected country and units.
How to read the result
- Read the main result first. The supporting figures for system a / year, system b / year, and difference / year explain how the estimate is built.
- The method is Heat demand ÷ system efficiency × energy price. Keep the units consistent and use values from the same time period.
Edge cases worth checking
When annual heat needed is unusual
Annual heat demand is the same for both systems. Double-check this input before relying on the result.
When system b energy price is uncertain
Maintenance and installation costs are excluded. Run a lower and higher value to see a useful range.
What changes the result most
Annual heat needed
Measure annual heat needed with the same unit shown beside the input. Convert first if your source uses another unit.
System A efficiency
Test a lower and higher system a efficiency. A small percentage change can move the final result more than expected.
System A energy price
Use a current amount for system a energy price. Include fees or recurring costs that belong in the same figure.
Try a different scenario
Small changes show whether the answer is stable or sensitive.
Annual heat needed: 10% lower
10,800 kWh heatSystem Bhas the lower energy cost
Annual heat needed: 10% higher
13,200 kWh heatSystem Bhas the lower energy cost
System A efficiency: 10% higher
99 %System Bhas the lower energy cost
Common mistakes
Check annual heat needed
Annual heat demand is the same for both systems. Make sure this matches the number you enter.
Keep system b energy price consistent
Maintenance and installation costs are excluded. Use the same units and time period throughout the calculation.
Do not rely on one heating system cost comparison scenario
Run a cautious case and an optimistic case. The range is often more useful than one exact-looking number.
Use this result well
Which heating option costs less under your rates?
Actual tariffs, weather, equipment behavior, and fixed charges can change the bill.