Calculator

Which tariff is cheapest for you?

Put in the quotes you have. We price each one on your own usage, over the next 12 months, whether the cap rises in January or not, with exit fees counted.

Verified: 23 October 2026 from Ofgem price cap and published supplier forecasts
How is this calculated?

1. Your usage

Your half-hourly download shows how much of your electricity lands in each time band, which is what decides a time-of-use tariff. The file is read in your browser and never uploaded.

No file? Switch to typing your yearly use; we’ll assume a typical home’s daily pattern.

2. The tariffs you’re weighing up

Copy the rates from each quote’s tariff details. Use the rates as quoted now, during the temporary zero rate of VAT on electricity.

Electricity

Gas

Electricity

Gas

Add:

3. What each would cost you

Fill in at least one tariff’s rates to see the comparison.

Independent calculator. We don’t pass your details to installers. We don’t earn commission from the result. We update underlying rates monthly and source everything from authoritative public data. See the full methodology.

Common questions

Should I fix my energy tariff now?
It depends on what happens to the price cap, which nobody knows for certain. Supplier forecasts put the January 2027 cap up about 26%, and Ofgem announces the real figure by 25 November 2026. A fix priced a little above today's cap wins if that rise happens and loses if it doesn't. This checker prices your actual quotes under both outcomes, so you can see how much you would gain or lose either way.
Why use my smart meter data instead of an annual figure?
Because time-of-use tariffs charge different prices at different times of day, and what you pay depends on when you use electricity, not just how much. A tariff with an expensive 4pm to 7pm peak can be cheap for one home and expensive for another with the same annual use. Your half-hourly download shows exactly how your use falls across a quote’s time bands. The file is read in your browser and never uploaded.
Why does a fix with no exit fee matter so much?
Because it turns a fixed price into insurance. If prices rise, you are protected. If they don’t, you can leave for free once the cap is announced, so the only cost is any extra you paid until then. The checker works that cost out for each fixed quote.