How Many Tonnes of Wood Pellets Do I Need for Winter?

How Many Tonnes of Wood Pellets Do I Need for Winter?

Most houses that heat with a pellet boiler burn between 2 and 6 tonnes of pellets per winter. A house that needs 15,000 kWh of heat per year and runs a boiler at 85% efficiency needs about 3.7 tonnes. You can work out your own number with one formula and your last heating bill.

The formula

Pellets per year (kg) = annual heat demand (kWh) ÷ (4.8 kWh/kg × boiler efficiency)

ENplus A1 pellets deliver roughly 4.6 to 5.3 kWh of heat per kilogram, so 4.8 is a fair planning value. Boiler efficiency is the share of that energy that reaches your radiators. Modern pellet boilers usually run at 85 to 92%, old stoves and boilers often sit lower.

Example: 15,000 kWh ÷ (4.8 × 0.85) = 15,000 ÷ 4.08 = 3,676 kg, or about 3.7 tonnes. Add 10% as a reserve for a cold February and you land at roughly 4 tonnes.

Where to find your annual heat demand

• Last year’s fuel bills. If you burned 1,500 litres of heating oil, multiply by about 10 kWh per litre to get 15,000 kWh. Gas bills are already in kWh.
• Energy certificate. Most EU countries list the heat demand of the building in kWh per m² per year. Multiply by the heated floor area.
• Rule of thumb. Poorly insulated houses use 120 to 200 kWh/m² per year, average houses 80 to 120, well insulated new builds 30 to 60.

Tonnes of pellets by house size

The table uses an 85% boiler and 4.8 kWh/kg. Hot water for the household is included in the demand figure.

House type	Heat demand per year	Pellets needed	With 10% reserve
Small, well insulated (80 m²)	8,000 kWh	2.0 t	2.2 t
Average flat or small house	12,000 kWh	2.9 t	3.2 t
Average family house (130 m²)	15,000 kWh	3.7 t	4.0 t
Larger or older house	20,000 kWh	4.9 t	5.4 t
Large, poorly insulated house	25,000 kWh	6.1 t	6.7 t

With a 90% boiler, cut each figure by about 5%. With a 75% boiler, add about 13%.

Which order size fits your number?

We sell pellets in 1, 3, 5 and 10 tonne options. Match your number like this:

• Up to 2 tonnes: one 1 t or 3 t order covers a small house or a stove used as a second heat source.
• 3 to 4 tonnes: one 3 t order plus a 1 t top-up, or a single 5 t order if you have the storage space.
• 5 to 6 tonnes: one 5 t order, with the reserve already inside it.
• 7 tonnes and more: a 10 t order, usually for large houses, farms or two buildings.

Check storage before you order. One tonne of pellets takes up about 1.5 m³, so 4 tonnes need about 6 m³ of dry space. Read our guide on pellet storage, humidity and quality before you decide where the pallets go.

Why buying the whole winter at once usually pays

Ordering your full tonnage before the heating season lets you lock in a price and avoids delivery delays during cold spells. Compare the options in our bulk vs bagged pellet cost analysis.

Ready to order?

See our ENplus A1 wood pellets for home boilers or DIN pellets for stoves that accept them. We deliver across Europe. Send us your annual heat demand and we will tell you which order size fits.

FAQ

How many bags of pellets is one tonne?

One tonne is 67 bags of 15 kg. A 4 tonne winter is about 267 bags.

How much do pellets cost per kWh?

Divide the price per tonne by 4,800 to get the price per kWh of fuel energy. A tonne at €300 costs €0.0625 per kWh before boiler losses. Divide by the boiler efficiency for the real heat cost.

Do I need more pellets with a stove than a boiler?

Not necessarily. A stove heats one or two rooms, so total consumption is often lower, but stoves have lower efficiency and rely on a second heat source.