How can you estimate your gas consumption or calculate it precisely? It’s simple – read your meter carefully and analyze the right information. You’ll then be able to predict your bill.


Heating costs represent a large proportion of the total energy bill in Belgian households. During the winter, people who use natural gas for heating know that the cold months will be expensive. Fortunately, there are a number of tricks for reducing your gas consumption. But in order to control your budget, you first need to learn how to calculate it. Do you use gas only for cooking or for hot water? Don’t worry: estimating your gas consumption will be useful for you too!

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1. Read your gas meter and convert the m³ figure into kWh

Reading the index on a gas meterThere are two steps to finding out your gas consumption. The first is to take a reading from your energy meter. This is very easy: simply calculate the difference between the current reading and the previous reading. This is the figure collected every year by your distribution system operator (DSO).

But if you want to control your spending better, you need to read the meter more frequently – monthly, for example. As soon as you notice your gas consumption increasing, you can make some adjustments. If you heat your home with natural gas, you can obviously expect a sharp increase during the winter months.

It is important to note that a gas meter measures the cubic meters (m³) supplied. It does not indicate the actual quantity of energy consumed. To calculate this, a second step is required: converting into kWh (kilowatt-hours). This involves multiplying the difference between the two readings by 10, which is the average energy value of gas (1 m³ = 10.3 kWh).


  • Reading on 5 January 2020: 24,000 m³
  • Reading on 5 January 2019: 22,000 m³
  1. Annual consumption: 24,000 – 22,000 = 2,000 m³
  2. Quantity of energy: 2,000 x 10 = 20,000 kWh

Based on the number of kWh consumed, your gas supplier can prepare your annual bill. This simply involves multiplying the energy consumed by the gas price stated in your energy contract.

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2. Estimate your gas consumption based on specific criteria

Reading your gas meter tells you your actual energy consumption. But what can you do if this is not possible? If you have just connected your home to mains gas, for example? In cases like this, you have no alternative but to estimate your consumption.

Several elements need to be considered when calculating your gas consumption:Gas consumption of a family of four

  • the habitable area of your home;
  • your use of natural gas: if gas powers your heating and hot water, you will use more than someone who only needs it for cooking;
  • the number of people in the home;
  • the lifestyle of the occupants: someone who is at home all day will use more gas than someone who is regularly absent;
  • whether you use a room heating system: a household that uses gas for heating but tops up the warmth with a wood or pellet burner or an electric radiator will inevitably see lower gas bills.
  • the insulation of your house or flat.

Clearly, your gas consumption will vary depending on the characteristics of your home and your consumer profile. This means it is difficult to evaluate, but you can make the process easier by doing free simulations online. If you wish, you can also call one of our advisers on 0800 37 369. They can calculate your gas consumption and suggest the best gas deal for your circumstances.

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3. Assess your consumption based on the average gas consumption in Belgium

As with electricity, it is possible to estimate your gas consumption without doing complex calculations. You can simply use the average consumption of a Belgian household based on its size and its gas use. While this will not give a precise result, it is still a useful way of getting a rough idea.

And if you are worried about underestimating or overestimating, you can always check your gas meter reading at regular intervals. After a few months, you should be able to identify any margin of error. Then there will still be time to revise your intermediate bills upwards or downwards with your gas supplier.

Average gas consumption per year in Belgium*
Type of customer Use of natural gas Annual consumption in kWh
Small consumer Cooking and hot water 2,326 kWh
Large consumer Cooking and hot water 4,652 kWh
Small consumer Cooking, hot water, and central heating 23,260 kWh**
Large consumer Cooking, hot water, and central heating 34,890 kWh

*Reference consumption figures supplied by CWaPE, the Wallonia energy regulator, and used for simulation purposes with no knowledge of actual consumption.

**For information, 23,260 kWh corresponds to the consumption of a typical residential customer (family of three).

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4. Use the gas consumption of the previous occupier as a guide

Have you just moved into a house or flat that was previously inhabited? You can take advantage of this to ask the previous occupant how much gas they consumed to get an idea of how much your future bills will be. Don’t hesitate to ask for their consumption figures for the past few years as you will then be able to take an average and avoid too much discrepancy in your consumption forecast.

If the previous occupant does not know their gas consumption, ask them for their monthly installment amount and multiply it by 12 and then by 20. This will give a result in kWh. It will still be a very approximate estimate as the installment amount depends on the supplier and the contract. It’s also possible that the installment amount was not appropriate for the person’s actual consumption.

In summary, while this method is quick and easy, it leaves something to be desired in terms of accuracy. For one thing, the previous tenant or owner’s consumption habits may be very different from your own. This would be the case, for example, if the previous occupant lived alone while you have a large family. So feel free to adjust the number of kilowatt-hours, since underestimating consumption can lead to a large adjustment bill at the end of the year. This makes sense because, as a reminder, the annual (or adjustment) bill is based on your actual gas consumption.

What can you do if your consumption has been underestimated?

A person shocked by the amount of their gas billWhen you read your energy bill, you may have a nasty surprise: the amount of your adjustment bill is very high. There are two possible reasons for this:

  1. You consumed more gas than the previous year for various reasons (colder and longer winter, bigger household, heating your home to a higher temperature, etc.).
  2. Your energy supplier, or you yourself, may have underestimated your gas consumption when agreeing on the supply contract.

In such a situation, you have no choice but to pay your bill. If you refuse, you risk having your gas cut off. However, you can always ask your supplier to spread out the payments with a debt repayment plan. This means you will be able to settle your gas bill at your own pace.

For the following year, your supplier will adjust your installment bills to take the additional consumption into account. This will mean having to pay higher intermediate bills, but you will be protected from any further unwelcome surprises. However, this is only true if you keep an eye on your consumption.

In case of technical issues (meter, boiler, etc.)

Note: an unusually high gas bill may be due to a meter malfunction. Though this problem is rare, it’s worth mentioning it to your DSO. Other possible causes include a leak in your gas-powered appliance (cooker, water heater etc.) or a fault in your boiler. Boiler faults generally arise after a gas boiler service that was carried out poorly (or not at all) or as a result of incorrect settings. Remember to check regularly that your appliances are in good condition – for the sake of your wallet and also for your own safety.

How can you reduce your gas consumption?

Natural gas is associated with three areas of consumption:

  1. heating;
  2. hot water;
  3. cooking.

In other words, there are various things you can do to reduce your gas bill. In terms of heating, you have several solutions: improving your home insulation, lowering the temperature by a degree, or installing a more efficient heating system.

For hot water, take showers rather than baths and set the temperature of your gas-powered water heater between 55 and 60°C. There’s no need to go any higher as this temperature is sufficient to limit any proliferation of bacteria and microbes.

Finally, cook smart! For example, when you’re heating water, put a lid on the pan. And to avoid excess gas consumption and save energy, clean your gas cooker burners regularly.

Want more advice on how to reduce your gas bill or find the best gas price? Call our advisers free on 0800 37 456 – they will listen to your personal situation and suggest tailored solutions.

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In conclusion, if you want to estimate your gas bill and react quickly if your consumption increases, you have several options available. The first is to read your meter regularly to find out your actual consumption. If that is not possible, you can always estimate your consumption based on the average consumption in Belgium or with a calculation based on the characteristics of your home and your household. Finally, if you move house, consider obtaining consumption information from the previous occupants. Which option will you choose?

>> Read also: Five practical tips to estimate your electricity use

Now that you know how to estimate your gas consumption, you know better how to reduce it! However, keep in mind that it is not advised to over-lower your heater or your use of hot water. For your wellbeing, make sure to maintain an acceptable level of comfort in your home. If you fear for your budget, you always have the possibility to compare your energy plan with the other options on the market. can help you through the whole process, so what are you waiting for to get a new and cheaper gas contract?

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