Electricity Bill Check Calculator
Recalculate a flat-rate electricity usage and daily-supply subtotal, then compare it with the bill total entered.
Your results
Calculation breakdown
- Entered-components subtotal
- Subtotal = (usage × usage rate) + (daily supply charge × days)
Worked example
900 kWh at 30c/kWh plus a $1.10 daily charge over 90 days gives an entered-components subtotal of $369. A $380 bill total is $11 above that subtotal.
Assumptions
- This comparison alone does not establish that a retailer made a billing error.
- Excludes time-of-use and controlled-load bands, fees, discounts, rebates, feed-in credits and prior balances.
- No GST adjustment is made; compare rates and totals on the same GST basis.
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How this calculator works
Enter flat-rate usage in kWh, billing days, the usage rate in cents per kWh and the daily supply charge in dollars to recalculate those components and compare their subtotal with the bill total.
Check the main parts of an electricity bill
For a flat-rate plan, multiply electricity use in kilowatt-hours by the usage rate, then add the daily supply charge for every day in the billing period. Enter the usage rate in cents per kWh and the supply charge in dollars per day.
The result is only the subtotal for those entered components. Time-of-use and controlled-load bands, fees, discounts, rebates, solar feed-in credits, prior balances and GST adjustments are not separate inputs in this version.
- Usage charge = kWh × cents per kWh
- Supply charge = billing days × daily charge
- Check whether rates and totals include GST
Actual versus estimated meter readings
Check whether the retailer marked the reading as actual or estimated. An estimated reading can later be adjusted when an actual reading becomes available, so it may not match your meter or smart-meter data for that period.
This calculator checks the arithmetic of the figures entered but cannot establish a billing error. Reconcile every omitted bill line, then contact the retailer if the tariff, meter reading, billing dates or account adjustments still appear wrong.
Official sources and assumptions
Check the official or authoritative references used to review this calculator's rates, formulas and assumptions.
Frequently asked questions
What if my recalculated total doesn't match my bill?
Check whether the bill also contains time-of-use or controlled-load charges, fees, discounts, rebates, solar feed-in credits, prior balances or GST treatment not represented by the four inputs.
Where do I find my usage rate and supply charge?
Both are listed on your bill, usually in a section titled 'your electricity charges' or similar. Enter usage in cents per kWh and convert the daily supply charge to dollars per day, for example 110 cents as $1.10.
Does this include GST?
There is no separate GST adjustment. Use rates and a bill total on the same GST basis, and check the original bill if GST is itemised separately.
Content responsibility
Maintained by CalcAussie and last updated 30 September 2026. Checks applied: calculation method, worked examples, Australian terminology, material assumptions, official references where an external rule applies, and user-facing limitations.
Calculator results remain estimates based on the figures entered. Check material decisions against current official information and report a suspected error so it can be reproduced and corrected.
Actual prices, usage, efficiency and savings vary by provider, equipment, location and behaviour.