How to convert your gas units to kwh

by | Jan 19, 2024 | Electricity & Gas

Are you trying to convert your meter reading from gas units to kWh?

While energy companies usually require you send them readings in kWh, many older gas meters still measure in m³ and f³ (cubic metres and cubic feet). Here’s how to accurately convert your readings so you can make sure you’re paying the right amount for your energy.


How to convert gas units to kWh

Here’s how to convert your gas units into kWh:

  1. Take a reading from your gas meter. Use our guide here if you’re not sure how.
  2. Check if your meter is metric or imperial.
  3. Convert your reading using the correct formula below.

Is my energy meter metric or imperial?

A metric meter will measure in m³ and have four digits before the decimal point. An imperial meter will measure in f³ and have six digits before the decimal point.


How to convert m³ gas units into kWh

Once you have your meter reading in m³ you can convert it to kWh using this formula.

Cubic meters (m³) used x calorific value* x Correction factor (1.02264) ÷ kWh conversion factor (3.6) = kWh.

*see below for how to find your calorific value.

If we use the average calorific value of 40.0 and say that you used 200m³ of gas last month the calculation looks like this:


 Meter Reading ()

 x Calorific Value (MJ/m³)

 x Correction Factor

÷ kWh Conversion Factor

= kWh Reading


 x 40.0

x 1.02264 

÷ 3.6

 = 2273 kWh



How to convert f³ gas units into kWh

You can convert a gas reading in f^3 using almost the same formula – you just need to convert the units to m^3.

Therefore, the formula will look like this:

Cubic feet (ft3) used x metric conversion factor (0.0283) x calorific value x correction factor (1.02264) ÷ kWh conversion factor (3.6) = kWh

If we again use the average calorific value and assume you used 200 ft^3 of gas the calculation would be:


 Meter Reading ()

x Metric conversion factor

 x Calorific Value (MJ/m³)

 x Correction Factor

÷ kWh Conversion Factor

= kWh Reading



 x 40.0

x 1.02264 

÷ 3.6

 = 64.3 kWh



What is the calorific value shown on my energy bill?

The calorific value is a measure of how much energy your gas generates. It should vary between 37.5MJ/m³ and 43.0MJ/m³, with 40.0 being an average.

The average calorific value of the gas you received this month can be found on your energy bill.

The unit, MJ/m³ means Mega Joules of energy produced per m³ of gas supplied.


Learn more about converting gas units to m³

If you still have questions about converting gas units to kWh, you can read the full government guidance here.

These regulations are the ones followed by energy companies, so you can use this guidance to make your conversions as accurate as possible.


Never stress about moving again.

Get all your utilities sorted, for free.

Start now
Never miss an offer again!
Exclusive offers & money saving tips

© Please Connect Me

Privacy Policy | Terms & Conditions

Our Services










About us





Support centre

Cookies settings

Sign up to our newsletter
For exclusive offers, money saving tips & more