This document provides instructions for calculating gas usage based on meter readings in either cubic meters (metric) or hundreds of cubic feet (imperial). It explains that meters measure usage in these units but bills are in kWh, so a conversion is needed. The key steps are: 1) Subtracting the previous meter reading from the current one to get usage in meters cubed or hundreds of cubic feet. 2) Multiplying this usage by adjustment, calorific value, and conversion factors to calculate kWh used. 3) Using the kWh and billing rate to calculate cost or dividing kWh by time between readings to get hourly usage. Contact information is provided for disputing bills with your gas provider if needed.

1. How to Calculate Your Gas
Usage
For Imperial and Metric Meters

2. So, your meter registers
 meters cubed (m3) if your meter is metric
 hundreds of cubic feet (ft3(x100)) if your meter is
imperial

3. But then you’re billed in kWh!

4. So, how are you supposed to calculate
your bill?

5. First, you need a minimum of 2 meter
readings
 ‘Why’ will become apparent …

6. Note the dates of your readings so that
you have a period of usage
 If you want to calculate your hourly usage, you
need the times of the readings also

7. Once you have these …
 Minus the previous reading from the latest
 Then minus the date and time of the previous
reading from the latest
This is why you needed a minimum of 2

8. You now have …
 The meters cubed or hundreds of cubic feet you
have used
 The timeframe within which they were used

9. Now you need to do the conversion …

11. Conversion Equation …
 And for metric meters:
 ((((Hundreds of cubic feet x 2.83) x Adjustment
Factor) x Calorific Value) / Conversion Factor)
 For imperial meters:
 (((Cubic meters x Adjustment Factor) x Calorific
Value) / Conversion Factor)

12. What was that?
 Adjustment Factor?
 Calorific Value?
 Conversion Factor?

13. If you have an imperial meter, first
multiply your hundreds of cubic feet by
2.83
 This is to convert it to m3 for the rest of the
equation

14. The Adjustment Factor, AKA the
Correction Factor is used to account for
temperature and atmospheric conditions
at your site
 It’s usually 1.02264
 Check your latest bill for the latest information

15. The Calorific Value is the amount of
energy in your gas and it’s constantly
monitored by TRANSCO (The National
Grid)
 It can range from 37.5 to 43.0

16. The Conversion Factor is just to convert
seconds to hours
It’s 3.6

17. Here’s an example …
 So your first reading is:
 142406 (metric)
 And your second is:
 142424 (metric)

18. Firstly, minus 142406 from 142424 to get
your m3 usage
Your result will be 18

19. Then multiply this by the
Adjustment Factor (usually 1.02264)
Your result will be 18.40752

20. Next, multiply by your Calorific Value
(we’ll use 39.3)
Your result will be
723.415536

21. Lastly, divide that by 3.6
And you’ll have 200.94876

22. And that’s how many kWh you have
used!!!

23. Image courtesy of stockimages at FreeDigitalPhotos.net

24. So now you can …
 Use your pence/kWh to calculate what that has
cost you
 Divide the number of kWh by the number of hours
it took to use them to calculate your average kWh
usage per hour
(If you remembered to take the times of the
readings)

25. Happy Days!!!

26. Got a dispute with your provider?
 Talks getting nowhere?

27. If all else fails, you can contact the
Ombudsman:
 Email: osenquiries@os-energy.org
 Phone: 0330 440 1624
 Fax: 0330 440 1625
 Textphone: 0330 440 1600
Office closed at the weekends, on bank holidays and
between Christmas and New Year
 Web: www.ombudsman-services.org/energy.html#

28. Hope this was helpful
Thanks for watching