How the Heating Cost Calculator Works
This calculator estimates how much useful heat your house needs based on floor area, insulation quality, and heating hours. It then compares the fuel or electricity required by different heating systems.
Useful Heat Demand
The calculator first estimates heating power from area and insulation level:
Then it estimates the useful heat needed for one heating day:
Fuel and System Cost Formulas
For a heating system with efficiency below 100%, the required input energy is higher than the useful heat delivered:
For fuels sold by volume or mass:
For a heat pump:
Assumptions Used
| Heating option | Efficiency / COP | Energy content |
|---|---|---|
| Electric resistance heating | 96% | 1 kWh per kWh |
| Petrol heating | 70% | 12.8 kWh per liter |
| Natural gas heating | 95% | 10.8 kWh per m³ |
| Pellet heating | 85% | 4.37 kWh per kg |
| Heat pump | User-entered COP | Uses electricity |
Annual Cost Method
The annual estimate combines full heating days and partial heating days:
For example, if partial heating days use 40% of the winter heating load, enter 0.4 as the partial heating load factor.
Frequently Asked Questions
Why does insulation change the heating cost?
Poor insulation increases the heat load per square meter. That means the house needs more heat input for the same floor area and heating time.
Why is a heat pump compared using COP?
COP means coefficient of performance. A COP of 3 means the heat pump delivers about 3 kWh of useful heat for each 1 kWh of electricity consumed under the assumed conditions.
Are fuel prices included automatically?
No. Enter your own local prices. Energy prices change often and vary strongly by location, supplier, taxes, and contract.
Can this calculator size my heating system?
No. This is a cost-estimation tool, not a heating-system sizing tool. Equipment sizing should be checked by a qualified professional using local design temperatures and building heat-loss calculations.