Knowing your annual consumption helps you choose a sensible tank size, budget accurately and spot when something is wrong with your boiler. Here is a practical way to estimate it.
The quick answer
| Home | Typical yearly use |
|---|---|
| 1–2 bedroom flat or cottage | 1,000–1,500 litres |
| 3 bedroom house | 1,800–2,500 litres |
| 4+ bedroom detached house | 2,500–3,500+ litres |
These ranges assume oil is used for both heating and hot water. Older, poorly insulated or exposed properties can use considerably more.
Working it out yourself
One litre of kerosene contains roughly 10.3 kWh of energy. A modern condensing boiler converts around 90% of that into useful heat; older non-condensing models may manage 70–80%. So:
Litres per year ≈ annual heat demand (kWh) ÷ (10.3 × boiler efficiency)
Your heat demand is often listed on your Energy Performance Certificate (EPC) under "space heating" and "water heating". For example, a home needing 18,000 kWh a year with a 90% efficient boiler would use about 18,000 ÷ (10.3 × 0.9) ≈ 1,940 litres. The same home with a 75% efficient boiler would need about 2,330 litres.
Use your own records
The most reliable figure comes from your delivery history. Add up the litres delivered over a full year and adjust for the difference between your tank level at the start and end. If you have a remote tank monitor, its app may do this for you.
Signs your consumption is too high
- A sudden jump in usage without a colder winter could mean a leak or theft — check the tank and pipework.
- Sooty smells or a yellow flame suggest the boiler needs servicing.
- Radiators that are cold at the top need bleeding, which wastes heat until fixed.
Once you know your annual figure, plug it into our calculator to see what a year of heating is likely to cost at today's prices.