Calculate your gas usage and standing charges separately.
Once both have been calculated, the calculator will combine them
to estimate your total gas cost.
%
Domestic gas is normally charged at 5% VAT.
If the rates you enter already include VAT, set this to 0%.
1
Gas Usage Calculator
Enter your meter readings and gas tariff details to
calculate how much gas you have used and what that
usage costs.
Meter type
Meter readings
Gas conversion details
MJ/m³
The calorific value tells us how much energy the gas
contains. Use the figure shown on your gas bill where
possible.
Gas changes volume with temperature and pressure.
The correction factor adjusts the measured volume
to standard conditions.
Gas unit rate
p/kWh
Gas usage result
Gas units used
—
Gas volume
—
Energy used
—
Gas usage cost including VAT
—
Usage calculated.
Now calculate your standing charges below to see your
total estimated gas cost.
A full calculation breakdown will be shown after both
parts have been calculated.
2
Standing Charges Calculator
Enter your standing charge and the dates that apply
to calculate the standing charges for the period.
p/day
Standing charge period
Enter the start and end dates for the period you want
to calculate.
Standing charge result
Number of days
—
Standing charges including VAT
—
3
Your Estimated Gas Cost
Complete both calculations above to see your combined
estimated gas cost.
Gas usage
Not calculated
+
Standing charges
Not calculated
=
Total including VAT
—
Full Calculation Breakdown
See how your gas usage, conversion, standing charges and VAT
have been calculated.
Gas usage calculation
1. Meter readings
2. Convert imperial units to cubic metres
Older imperial gas meters normally record gas in
hundreds of cubic feet. Each imperial meter unit is
approximately 2.83 cubic metres.
2. Apply the calorific value and correction factor
Calorific value tells us how much
energy is contained in the gas.
Volume correction factor adjusts
the measured gas volume for temperature and pressure.
3. Divide by 3.6
The calculation above gives energy in megajoules
(MJ). There are 3.6 megajoules in one kilowatt-hour,
so dividing by 3.6 converts the result into kWh.
4. Calculate gas usage cost
Standing charge calculation
1. Calculate the number of days
2. Calculate standing charges
VAT and total
1. Cost before VAT
2. Add VAT
3. Total estimated cost
This calculator provides an estimate. For the closest comparison
with your bill, use the calorific value, volume correction factor,
unit rate and standing charge shown on your bill or tariff.
If the rates you enter already include VAT, set VAT to 0% to avoid
adding it twice.
