Electricity Tariff Comparison Calculator
Compare two electricity tariffs that trade a daily charge against a usage rate — the annual cost of each at your usage, the saving, and the usage at which the cheaper one changes.
Tariffs bundle a fixed daily charge with a rate per kilowatt-hour, and one plan often has a higher charge with a lower rate.
How the electricity tariff comparison calculator works
Tariffs bundle a fixed daily charge with a rate per kilowatt-hour, and one plan often has a higher charge with a lower rate. Which is cheaper depends on how much you use: the break-even is the difference in daily charges over the difference in rates, scaled to a year. Below it the low-charge plan wins; above it the low-rate plan does.
Formula: annual = daily × 365 + usage × rate; break-even usage = 365 (d_A − d_B) / (r_B − r_A)
Worked examples
| Inputs | Cheaper tariff at your usage | Note |
|---|---|---|
| 4,500 kWh a year | Tariff B by 52.25 a year | the low-rate plan wins |
| A small user | Tariff A by 47.75 a year | the low-charge plan wins |
| With a discount on A | Tariff A by 73.75 a year | A pulls ahead |
FAQFrequently asked questions
Which tariff is cheaper?
It depends on your usage. A high daily charge with a low rate suits heavy users; a low charge with a high rate suits light ones. The break-even usage is where they swap.
Where do I find my annual usage?
On the bill, as kilowatt-hours for the period; multiply up to a year, or add four quarterly bills. Retailers' comparison sites also show it.
What about discounts?
Most apply to the usage charge only, sometimes conditional on paying on time. Enter them and the rate is reduced accordingly.
Do solar feed-in tariffs matter?
For a solar home, very much — a plan with a lower feed-in rate can cost more despite cheaper usage. This page compares import charges only.
How often should I compare?
Whenever a plan changes or once a year. Rates move and the cheaper plan for last year's usage may not be the cheaper one now.
Where these figures come from
- International Energy Agency — Energy Efficiency — appliance consumption and standby power context
- US Energy Information Administration — the federal energy statistics agency
Last checked: September 2026. Appliance power figures are typical ratings; check the label on your own equipment, which is authoritative for it.