If you know how much energy you've used in the last year (in £), but you're not sure how much was gas and how much was electricity, you can guess. Across the big energy firms’ standard tariffs, the split is 48% gas and 52% electricity , so that should give you an idea. If you spent £1,000 on energy, your gas bill would be £480 and your electricity bill £520.

For the best accuracy, enter your usage over the past 12 months in kilowatt hours (kWh).