Heating Oil Calculator

It varies enormously with size, insulation and climate — anywhere from 1,500 to 4,000 litres a year is common for a family home. Your own delivery history is a far better guide than any average.

On cost per kilowatt-hour of heat. Heating oil holds about 10.35 kWh per litre, so 75p a litre is roughly 7.2p per kWh before boiler efficiency — which is the figure to compare against a gas or electricity tariff.

Typically in the warmer months when demand is low, though it tracks crude oil and the pattern is not reliable. Buying ahead requires tank capacity and the cash to do it, which is what makes it a real saving for some households and not others.

Yes — it is the most useful thing this calculation produces. Setting aside the monthly equivalent turns a large irregular bill into a predictable one, which is exactly what a sinking fund is for.

Depends on tank size and consumption. A 1,200 litre tank on 2,500 litres a year lasts around 175 days of average use, though winter draws far faster than the average implies.

Yes. The figure per litre is the energy content of the fuel; a boiler at 85% efficiency delivers 85% of it as useful heat, so divide by the efficiency to get the real cost of heat in the room.

A dipstick, a sight gauge, or an electronic monitor. Electronic monitors are inexpensive and remove the guesswork that leads to running dry, which is worse than it sounds because it can draw sludge into the line.

Sediment from the bottom can be drawn into the fuel line and the burner usually needs bleeding and possibly a filter change. Keeping above a quarter tank avoids it.

Frequently. Group orders negotiate a lower price per litre, and in rural areas these are common and well established. The saving is real and requires only coordination.

Kerosene stores well for a year or more in a clean, sealed tank. Water ingress and sludge are the real risks rather than the fuel degrading, which is why tank condition matters more than turnover.

Prices are often lower when demand is low, though the pattern tracks crude oil and is not reliable. It requires tank capacity and the cash to buy ahead, which is what makes it viable for some households and not others.

A boiler at 85% efficiency delivers 85% of the fuel's energy as useful heat, so divide the cost per kWh of fuel by the efficiency to get the real cost of heat. Old boilers can be well below 80%.