How much fuel for a heating season? Pellet, coal, firewood and gas calculator
A 150 m² house insulated after 2000, with hot water for four people, uses about 4.5 t of pellets, about 3.1 t of eco-pea coal, about 12.3 mp of beech or about 1,784 m³ of gas per season. Pick a fuel and enter your house details to see bags, pallets, metres and zloty.
Example: 150 m² house, insulated
For the season you need about 4.5 t of pellets
- 298 bags of 15 kg
- 5 pallets of 975 kg
- 6.0-7.4 m³ of space if loose
Cost about 10,405 PLN a season
about 1,367 PLN in a heating season monthabout 867 PLN a month on averageheat demand about 18,600 kWh/yr
Prices from 11 October 2026, estimate
| Fuel | Per season | 1 kWh of heat | Season cost |
|---|---|---|---|
| Pellets | 4.5 t | 0.56 PLN/kWh | 10,405 PLN |
| Eco-pea coal | 3.1 t | 0.27 PLN/kWh | 4,960 PLN |
| Firewood | 12.3 mp | 0.33 PLN/kWh | 6,167 PLN |
| Natural gas | 1,784 m³ | 0.33 PLN/kWh | 6,069 PLN |
| LPG | 2,937 l | 0.51 PLN/kWh | 9,398 PLN |
Assumptions and formulaPrices from 11 October 2026
Heat demand
Q = 150 m² × 100 kWh/m² + 4 people × 900 kWh = 18,600 kWh
Amount of fuel
m = 18,600 kWh ÷ (4.9 kWh/kg × 0.85) = 4,466 kg
Season cost
4.466 t × 2,330 PLN/t = 10,405 PLN
Heating season month
8,391 PLN ÷ 7 + 2,014 PLN ÷ 12 = 1,367 PLN
- Hot water per person
- 900 kWh
- Calorific value
- 4.9 kWh/kg
- Bag
- 15 kgMurator: 15 kg bags on pallets of about 975-1,000 kg, Oct 2026
- Pallet
- 975 kgMurator: 15 kg bags on pallets of about 975-1,000 kg, Oct 2026
- Bulk density of A1 pellets
- 600-750 kg/m³DIN CERTCO, A1 pellet requirements under EN ISO 17225-2: 600-750 kg/m³
- Appliance efficiency
- 85 %
- Price
- 2,330 PLN/tMedian price of bagged pellets from producers and depots, Murator, Oct 2026
- Heating season length
- 7 moexample, hot water counted over 12 months
An estimate for a typical heating season. Delivery, fixed gas charges and the appliance with its servicing are not included.
How electricity, gas, pellet and coal prices have changed, month by month. Price history
Ready-made calculations
How to use the calculator
- Press the key with your fuel: pellets, eco-pea coal, firewood, natural gas or LPG.
- Enter the floor area, insulation standard and household size. If you know the heat demand in kWh, switch to entering it directly.
- Check the price and appliance efficiency. For firewood pick the species and water content, for gas you can enter the conversion factor from your bill.
- Click Calculate usage. The result then updates with every change, and the button under it copies a link to the result.
How much fuel a 150 m² house uses
A 150 m² house insulated after 2000 needs about 15,000 kWh of heat for space heating, and about 18,600 kWh with hot water for four people. At the calculator's default prices that is about 4.5 t of pellets for about 10,405 PLN or about 3.1 t of eco-pea coal for about 4,960 PLN per season.
The same heat comes from about 12.3 mp of seasoned beech (about 6,167 PLN at e.g. 500 PLN/mp), about 1,784 m³ of natural gas (about 6,069 PLN) or about 2,937 l of LPG (about 9,398 PLN at e.g. 3.20 PLN/l). The table under the result shows this comparison for your house and prices.
How we calculate the amount of fuel
Heat demand comes from the same formula as the heating cost calculator: floor area times the rate for the insulation standard, plus about 900 kWh per person for hot water. We divide it by the appliance efficiency and then by the energy in one unit of fuel.
Values used: pellets 4.9 kWh/kg with an 85% boiler, eco-pea coal 7.5 kWh/kg with an 80% boiler, seasoned beech 1,885 kWh/mp with a gasification boiler at e.g. 80%, natural gas 10.972 kWh/m³ with a 95% condensing boiler, propane about 6.67 kWh/l. Energy in firewood comes from the tables of the Bavarian forestry institute LWF for four species and four levels of water content.
Cost in a heating season month and what is left out
A monthly average over the whole year understates winter spending, because you buy fuel mainly for the heating season. So the calculator divides the space heating cost by the months of the season (e.g. 7) and the hot water cost by 12. A 150 m² house on pellets comes to about 1,367 PLN in a season month against about 867 PLN averaged over the year.
The result leaves out fuel delivery, fixed gas charges, buying and servicing the boiler and storage losses. Heat demand is an average for a typical winter: a colder season or a warmer house means more fuel.
Frequently asked questions
How many tonnes of pellets does a 150 m² house need per season?
A 150 m² house insulated after 2000 burns about 3.6 t of pellets for space heating alone and about 4.5 t if the boiler also heats water for four people. That is about 298 bags of 15 kg or 5 pallets of 975 kg.
How many m³ of gas does a house use in a year?
A 120 m² house insulated after 2000 with four people uses about 1,497 m³ of gas, and a 150 m² house about 1,784 m³. The calculator converts kWh to m³ with 10.972 kWh/m³. If you have a bill, enter the factor printed on it.
How much firewood do I need for winter?
A 150 m² house insulated after 2000, with hot water from a wood boiler, burns about 12.3 mp of seasoned beech or about 15.3 mp of pine. Fresh wood with about 50% water gives less heat, so you need more metres.
Why is the cost in a season month higher than the average?
Space heating is divided only by the months of the heating season, e.g. 7, and hot water by 12. A 12-month average spreads the winter cost over the summer, so it is lower. Change the season length in the Heating season field.