MundoKit

Energy Tariff Standing Charge Calculator

Enter two single-rate quotes, days and consumption. See both bills and the usage level where the cheaper tariff changes.

Inputs
p/day
p/kWh
p/day
p/kWh
days
kWh
Find actual annual kWh on your bill or supplier account. Presets use one 365-day year.

Results

Cheaper tariff for entered usage
A saves £9.50
Tariff A cost
£709.50
Tariff B cost
£719.00
Consumption crossover for this period
2,190 kWh
  • Custom consumption: use actual kWh from your bill or supplier account.
  • Below the crossover, tariff A is cheaper. Above it, tariff B is cheaper.
  • Use VAT-inclusive quotes on the same basis. Excludes exit fees, discounts, debt and future rate changes. Compare one fuel at a time.

Results update as you type. The share link stores your inputs after the # in the address, which is not sent to our server, but anyone you send it to can read them.

How it works

Ofgem describes bills as usage charges plus standing charges. Cost in pounds = (days × standing charge in pence + kWh × unit rate in pence) ÷ 100. Equating both bills gives crossover kWh = days × (standing B − standing A) ÷ (unit A − unit B). Equal unit rates have no single crossover. A negative crossover is outside non-negative consumption.

Quotes are editable examples, not current cap rates. Keep taxes and discounts consistent. Money is rounded to pennies and crossover to three decimals; intermediate values are not rounded.

Custom consumption starts with a 2,000 kWh example. Find actual annual kWh on your bill or supplier account. The Ofgem presets effective July 2026 use 2,500 kWh electricity or 9,500 kWh gas over one 365-day year. Presets are comparison assumptions, not a forecast of your usage.

Worked examples

Low consumption

At 365 days, A at 30p/day and 30p/kWh costs £709.50 for 2,000 kWh. B at 60p/day and 25p/kWh costs £719.00. A saves £9.50; crossover is 2,190 kWh.

Higher consumption

With the same quotes and 3,000 kWh, A costs £1,009.50 and B £969.00. B saves £40.50.

Frequently asked questions

Is a lower standing charge always cheaper?
No. A higher unit rate can outweigh the daily saving as usage rises.
Does this use the latest price cap?
No. Enter your own quotes. Ofgem publishes regional rates for each cap period.
Can I compare gas and electricity together?
Run each fuel separately, then add the costs for the same period.
Are exit fees included?
No. Add exit fees and conditional discounts separately before deciding.

Sources

Last reviewed 2026-11-14; next review due by 2026-12-14. The method is written out above so you can check our math.