Gas Rate Calculator: Easily Work Out Your Gas Usage and Bill

The energy bill is something every household has to pay regularly, usually monthly. In some cases, depending on the supplier, consumers are charged through a single combined energy bill that may include electricity and gas consumption. Still, mostly these are charged separately as two bills. In the UK, homeowners are often worried about rising gas bills, especially during severe winters.

Although it is quite understandable that gas consumption is higher during the winter season, primarily due to consistent boiler use, the bill may still be unrealistically high. In most cases, homeowners start thinking the gas supply company might have charged them excessively. While this may not be the case, it would be appropriate for a homeowner to understand how gas consumption is calculated and, more importantly, how the gas bill is calculated.

On the other hand, understanding gas consumption and calculating the gas bill may also help improve your home's overall energy efficiency and control the cost of energy you pay. An accurate and precise gas rate calculator is the best solution to all these critical questions.   

This blog will provide complete guidance on how gas consumption is measured and how the gas bill is calculated, both manually and digitally. 

Measurement of Gas Consumption – Manual Method

The first step in calculating a gas bill is to understand how gas volume is measured. Currently, the most common unit of measuring gas consumption is cubic meters (m³), which is part of the metric system of measurements. However, in some cases, especially if the gas meter is quite old and installed in your home during the early 70s or even before that, the unit of measurement for gas consumption might be Cubic Feet (ft³).

Whatever the unit of measurement, it typically shows the volume of gas consumed by your home. However, it does not reflect the actual energy output that gas-supplying companies use to charge a home. It is measured in kilowatt-hours (kWh). It reflects the actual energy your home consumes. 

Hence, merely recording your gas meter reading cannot help you understand how much gas you have consumed, which the supplier will charge you for. To determine the actual energy consumed by your home, you need to convert the volume of gas, measured in cubic meters or cubic feet, into kilowatt-hours. Kilowatt-hour shows the number of units of gas your home consumes, which determines the actual bill the supplier will charge you.

Conversion of Gas Volume to Energy Units (kilowatt-hour kWh)

Before understanding how to convert gas usage to kWh, it is essential to understand what a kilowatt-hour (kWh) actually means. To better understand this concept, consider an electric heater. One kilowatt-hour (1 kWh) is the amount of energy (electricity) consumed by an electric heater rated at 1,000 watts continuously for 1 hour. The same concept applies to gas consumption. 1 kWh of gas consumption is equal to the volume of gas that must be burned to produce the same heat energy as an electric heater of 1,000 watts would consume continuously for 1 hour.

In the UK, the standard formula used to convert the gas consumption into kilowatt-hours (kWh) is as follows:

• For gas meters working under the old Imperial System - 1 kWh = (the Volume of Gas Consumed x Conversion Factor x Calorific Value) / 3.6
• For gas meters working under the new Metric System, 1 kWh = (the Volume of Gas Consumed x Calorific Value) / 3.6

Here, the description of different terms is as follows:

• The Volume of Gas Consumed – it is the difference between the previous and current meter readings, which are shown in your meter in terms of units (volume) of gas consumed. You will need the last month's meter reading, which is on the previous gas bill. Subtract it from the current reading to reach the actual units or volume of gas consumed during the month. 
• Conversion Factor – This factor is required to convert cubic feet to cubic meters if your meter uses the Imperial system (Old meters) instead of the Metric System (New meters). The conversion factor is 2.83. If your meter reading is given in cubic meters, skip this factor.
• Calorific Value – It is the energy content of the gas, which usually ranges between 37.5 and 39.5 MJ/m³ or 1.02264. The exact calorific value is often mentioned on the gas bill. You may use that value for correct calculations.
• Conversion of Megajoules into kilowatt-hours – The value that is used to convert the energy from megajoules (MJ) into kilowatt-hours (kWh) is 3.6.

This is the manual method of calculating your gas consumption. By putting the correct values in the above-referred formula, you can calculate the energy (gas) consumption of your home in terms of kWh. For an easy calculation, you need to proceed as follows:

1. First, you would need to convert the gas volume from cubic feet to cubic meters if you have an old meter that uses the Imperial System of measurement. If your gas meter already shows measurements in cubic meters, skip this step.
2. Next, either find the exact calorific value from your previous gas bill or enter 1.02264. However, to achieve a perfect calculation, you must enter the actual calorific value as stated on your gas bill.
3. The last step is to divide the resultant figure from the above two steps by 3.6. By doing so, you will get the gas consumption in kWh. 
4. Once the gas consumption in kWh is calculated, multiply it by the gas rate charged by your gas supplier. This will give you the exact amount payable by you for the month under reference. 

Calculation of Gas Consumption With “Gas Rate Calculator”

Although one can easily calculate gas consumption and the energy bill manually using the above formula, it is difficult for those not comfortable with mathematical calculations. Moreover, it is somewhat lengthy.

Many websites provide the facility to calculate gas consumption and energy bills digitally, often referred to as "Gas Rate Calculator" or "gas bill calculator". These calculators are also available as mobile applications for Android and iOS devices. These digital tools work efficiently and mostly deliver accurate results by converting gas consumption volume into energy units (kWh). Many such apps and websites can also estimate your energy bill if you know your gas supply package value. 

Mostly, you would need to provide the following information to get your estimated gas bill:

1. Previous meter reading.
2. Current meter reading.
3. Type of your gas meter, whether Imperial or Metric.
4. The Calorific Value, which can be found on your last gas bills.
5. Gas Supply Package or Tariff: the cost of gas per kWh.

Once you enter the values above correctly in the respective boxes, the gas rate calculator provides the following information/calculations:

1. Amount of gas consumed in terms of kilowatt-hour (kWh).
2. Estimated total cost in £.
3. Average gas usage is often worked out on daily or hourly usage. 
4. Some of the Gas Rate Calculators provide additional information, known as "appliance gas rate tests". This information is essential for gas safety engineers, who must check whether a gas appliance, such as a cooker or boiler, is operating correctly and efficiently.

Conclusion

Gas consumption, reflected in the shape of a gas bill, is something you often ignore. But at times, especially when you receive a gas bill that exceeds your expectations, knowing how gas suppliers calculate your home's gas consumption becomes of interest to you. It not only helps you understand the procedures gas companies use to send your energy bill, but also allows you to identify where you are wasting money on excessive usage or gas waste.

Gas rate calculators, available free online on various websites and in mobile applications, are a good source for estimating your gas consumption and energy bills. You can get the desired calculation by entering the relevant values. On the other hand, you can also manually calculate your gas usage and energy bill by following the procedure explained above.