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Last updated: 13 December 2021
When you're assessing your energy bills, or running an energy comparison to check you are getting the best deal, you'll notice that the prices charged on your gas bill don't necessarily equate to the numbers ticking over on your gas meter. This is because, while gas running through your meter is measured in M³, your usage of gas in relation to your energy bills is measured in kWh.
It's useful to be able to convert these two units accurately, because having access to both will allow you to compare your actual usage to the amount you've been billed for. This is useful as many energy companies bill you for gas using a system of forecasting, based on many factors.
Read our handy conversion calculator, and to learn how to convert your gas meter reading into the exact amount of gas you've used, in kWh.
How to read a gas meter
Reading a gas meter is a fairly simple task, so long as you're able to locate your meter! If you live in a rental property, your landlord should be able to tell you where to find the meter. In most properties though, the gas meter will either be in the kitchen, the hallway or outside in a cupboard or meter box.
Your meter records how much gas you use over a period of time. The main factor in taking your meter readings is to ensure you're checking how much the number changes over a standard time frame, for example one month. This allows you to compare your readings accurately with your bills, which will be broken down over a certain period, usually per month.
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What does M3 mean?
Gas meters in the UK come in two basic styles. Generally older meters, from before the metric switchover in the 60s, measure your gas usage in imperial units. This means the gas meter will be measuring how many cubic feet, or f³, of gas you are using.
Newer meters, including all meters installed today, measure your gas usage in M³, cubic metres. To avoid confusion between gas meters and cubic metres we'll only use M³ from now on. The first port of call when reading your gas meter is to determine which type of meter you have. Any gas meter will have either M³, f³ or possibly cubic feet written on it.
Once you've confirmed which type of meter you have, it's time to convert the gas units it displays into kWh, so you can calculate exactly how much you're paying for.
What does kWh mean?
kWh, or kilowatt hours, are the unit of measurement energy companies use when billing for gas. This is for consistency, as kWh are also used when billing for electricity and other energy sources.
The reason for this is that a kilowatt hour, which is the amount of energy used by an appliance maintaining 1kw or 1000w of power for 1 hour, can be compared across any energy using system. For this reason it's important to be able to convert your meter readings for gas, M³ to kWh, accurately.
Converting gas M3 to kWh
Using our calculator below, just insert your meter reading, in M³ from a metric meter or f³ if your meter is imperial. This reading should be the amount the number on your meter has changed over a certain time frame, for example one month.
The calculator will then tell you how much gas you used in kWh, which should be comparable to the amount of units on your gas bill for that time period.
1M³ of gas is generally equivalent to roughly 11.1868 kWh, although this can fluctuate slightly based on the calorific value of the gas your supplier is using. Check out our guide to learn more about comparing gas prices.
What to do if your estimated meter reading is too high or too low
Having put your meter readings into our gas M³ to kWh calculator, you may find that your actual gas usage is lower than the reading you've been billed for.
This can happen for a number of reasons, such as your energy supplier estimating your usage based on past figures when more occupants lived at the property, or because you've been away on holiday for an extended period with low or no usage.
If your gas bills are either too low or too high the best course of action is to contact your energy supplier and provide accurate meter readings. This will allow them to calculate your correct bill and either reimburse you, or negotiate repayments if you've been paying too little. Most energy suppliers provide a dedicated number on their website for meter readings to be submitted.
It's almost always best to contact your supplier as quickly as possible in these instances to prevent continuing issues.