kWh Cost Calculator
Convert electricity units to money — in both directions. Work out what a number of kWh will cost, or how many units a fixed budget buys, with an optional standing charge on top.
How much you want to spend (per month, or per top-up).
Optional fixed monthly fee.
Total cost
$0
for 300 kWh
Estimates only. Tiered and time-of-use tariffs price some units differently — check your plan's rate card.
How this kWh cost calculator works
Units to cost: cost = kWh × price per kWh + standing charge. Budget to units: kWh = (budget − standing charge) ÷ price per kWh. That second direction is the one prepaid-meter users need every top-up — it tells you exactly how much electricity your money buys after fixed fees take their cut.
kWh cost FAQ
How do I calculate the cost of kWh units?
Multiply the units (kWh) by your price per kWh, then add any fixed standing charges. 300 units at $0.15 each cost $45; with a $9 monthly standing charge the total is $54.
What is 1 kWh (one unit) of electricity?
1,000 watts used for one hour — enough to run a 100 W device for 10 hours, boil a kettle roughly 10 times, or wash one load of laundry. Meters and bills count these as "units".
How many kWh can I get for a fixed budget?
Subtract fixed charges from your budget, then divide by the price per kWh. With $50, a $9 standing charge, and $0.15/kWh: (50 − 9) ÷ 0.15 ≈ 273 kWh.
Why did the same number of units cost me more this month?
Tariffs change, and tiered pricing makes units above a threshold cost more — or time-of-use plans price evening units higher. Compare the rate line on both bills, not just the units.