Tariff break-even calculator

Two tariffs, one with the lower daily charge and one with the lower unit rate. There is exactly one usage level where they cost the same — above it one wins, below it the other.

Tariff A

Unit rate

p/kWh

Standing charge

p/day

Tariff B

Unit rate

p/kWh

Standing charge

p/day

Your electricity use

kWh a year

No registration
No email required
Instant calculation
Latest official Ofgem data

How to read the answer

If the break-even point is well below your own usage, the tariff with the lower unit rate is the cheaper one for you, and the gap grows the more you use. If it sits above your usage, the lower daily charge wins.

If your usage is close to the break-even point, the two tariffs are effectively the same price.

Mistakes that change the answer

Assuming the tariff with the headline-lowest unit rate is cheaper regardless of usage.
Comparing a gas figure on one tariff with an electricity figure on another.
Ignoring exit fees, which can outweigh a small annual difference.

Common questions

Is a lower unit rate or a lower standing charge better?

Neither in the abstract. It depends on whether your usage sits above or below the break-even point this tool calculates.

Does this work for gas as well?

Yes. Enter both tariffs' gas figures instead of their electricity figures.

See whether you could pay less

Your results above are based on official Ofgem figures and your own numbers. Switching is optional and nothing here changes what the calculation says.

Compare your tariff against another

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