Heating Oil Tank Calculator

Use this oil tank calculator to estimate your tank capacity, current oil level and how much space may be available for your next delivery.

Enter your tank shape, approximate dimensions and current fill level to get a rough estimate of how many litres your tank may hold, how much oil could be left, and how much heating oil you may be able to order safely.

This tool is designed as a planning guide only. Tank sizes, gauges and measurements can vary, so always check your tank label, speak to your supplier, or ask a qualified professional if you are unsure.

Estimate only

Tank Calculator

Estimate tank capacity, current contents, safe order room, and the likely cost to fill that available space.

Step 1 of 2

Check your tank room

Select the tank shape that most closely matches your oil tank.
%
Use a gauge reading or your best estimate.
cm
cm
cm

Estimated capacity

0 litres

Current oil in tank

0 litres

Safe order room

0 litres

This allows space below the safe fill level.

How the oil tank calculator works

The calculator uses your tank dimensions and chosen tank shape to estimate the approximate volume of the tank. It then uses your current fill level to estimate how much oil may already be in the tank and how much safe order room may be available.

The safe order room figure is based on leaving space in the tank rather than filling it to the absolute top. This helps allow for expansion and reduces the risk of overfilling, but it should still be treated as an estimate rather than a guaranteed delivery amount.

Why the result may not be exact

Oil tanks come in different shapes, sizes and designs, and many domestic tanks are not perfect rectangles or cylinders. Tank gauges can also be inaccurate, especially older float gauges or sight gauges. Small measurement differences can make a noticeable difference to the estimated number of litres.

For the most accurate result, check whether your tank has a manufacturer’s label showing its official capacity. If you are arranging a delivery and are unsure how much oil to order, tell the supplier your tank size, current gauge reading and any access details before booking.

Before ordering heating oil

Before placing an order, it is worth checking:

  • Your current tank gauge reading
  • Whether the tank is easy for a tanker driver to access
  • Whether there are gates, narrow lanes or long hose requirements
  • Whether your supplier has a minimum order amount
  • Whether the quoted price includes any delivery charge

You can also use the quote comparison calculator to compare supplier prices, or the supplier enquiry helper to create a clear message to send when requesting a quote.