How much oil does a typical UK home use per year?

A typical UK home with oil-fired central heating uses between 1,500 and 2,500 litres of kerosene per year. A well-insulated smaller property might use as little as 1,000 litres, while a larger or poorly insulated house could use 3,000-4,000 litres. The average is around 1,800-2,200 litres per year. Actual consumption depends heavily on property size, insulation levels, local climate, and thermostat settings.

Do I need a bunded oil tank?

Under UK Building Regulations (Approved Document J in England, equivalent standards in Scotland and Wales), a bunded tank is required if the tank is within 10 metres of a watercourse or borehole, or if the tank capacity exceeds 2,500 litres in a controlled area. OFTEC recommends bunded tanks for all new installations regardless of location. A bund must hold 110% of the tank's capacity to contain any spillage. Many insurers now require bunded tanks as standard.

What are the standard oil tank sizes in the UK?

Common UK domestic oil tank sizes are: 1,100 litres (standard single-skin), 1,225 litres (slim-line), 1,400 litres, 1,800 litres, 2,500 litres, and 3,500 litres. The most popular domestic sizes are 1,100L and 1,225L for smaller properties, and 2,500L for larger homes or those wanting fewer deliveries. Tanks are available in plastic (polyethylene) or steel, with plastic being the most common for domestic use.

How far should an oil tank be from the house?

Under UK Building Regulations, an oil tank must be at least 1.8 metres from any part of the building (non-fire rated wall), any opening (door, window, vent), and from the boundary of the property. If the building wall is fire rated, the distance can be reduced. The tank must also be at least 760mm from a non-fire-rated eaves overhang. There must be a concrete or paved base extending at least 300mm beyond the tank on all sides.

How often should I get an oil delivery?

Most domestic oil users order every 6-12 weeks during the heating season, with less frequent deliveries in summer. Ordering in larger quantities (500+ litres) usually gets a better per-litre price. Joining an oil buying syndicate or co-operative can also reduce costs by 2-5p per litre. Monitor your tank level regularly — running out of oil can introduce air into the system, requiring a boiler service to restart. Many suppliers offer automatic top-up services based on weather and estimated usage.

Oil Tank Sizing Calculator — What Size Oil Tank Do I Need?

Calculate the right oil storage tank size for your heating system based on boiler output, annual usage and delivery frequency. Includes bund sizing per OFTEC standards.

Boiler Output

Check your boiler data plate for output rating

Estimated Annual Usage

Typically 1500-2500 hrs/yr; avg UK is ~2000

Delivery Frequency

How often you want oil delivered — less frequent = larger tank needed

Include bund (secondary containment)

Bund must hold 110% of tank capacity — required in many locations

Oil Price per Litre (optional)

Enter current kerosene price for annual cost estimate

How We Calculate This

This calculator estimates annual oil consumption and recommends a standard tank size based on your boiler output, estimated annual usage hours, and delivery frequency.

The formula

Litres per hour = Boiler output (kW) ÷ Boiler efficiency (90%) ÷ Energy content of kerosene (10.35 kWh/L)

Annual consumption = Litres per hour × Annual usage hours

Litres per delivery = Annual consumption × (Delivery weeks ÷ 52)

Assumptions

Boiler efficiency: 90% (modern condensing oil boiler)
Kerosene energy content: 10.35 kWh per litre (standard 28-second kerosene)
Usage hours: Typically 1,500-2,500 hours/year depending on climate and property
Tank buffer: 20% added to delivery volume for safety margin

Bund sizing

A bund (secondary containment) must hold 110% of the tank's full capacity. This is required by OFTEC Technical Book 3 and Building Regulations Approved Document J. Bunded tanks have this containment built in; for single-skin tanks, a separate bund wall or tray must be constructed.

Standards

Oil tank installations must comply with OFTEC standards, Building Regulations Approved Document J (Combustion appliances and fuel storage systems), and BS 5410 (Code of practice for oil firing). Installation must be carried out by an OFTEC registered technician.

Frequently Asked Questions

Last updated: February 2026

All calculations are estimates. Verify with your supplier.

Oil Tank Sizing Calculator — What Size Oil Tank Do I Need?

How We Calculate This

The formula

Assumptions

Bund sizing

Standards

Frequently Asked Questions

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