Electrical · Free Calculator
Electricity Cost Calculator
Work out how much energy a load uses and what it costs to run, from its power, running hours and your tariff.
kWhDaily, monthly, yearlyAny tariffMotors and heaters
kW
%
h
days
per kWh
Energy per day96 kWh
Cost per day864.00
Cost per month (avg)23,760
Cost per year285,120
Energy per year31,680 kWh
How this result was calculated
- kWh per day = 7.5 kW × 0.8 × 16 h = 96
- Yearly cost = 96 × 330 × 9 = 285,120
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Energy and Cost Formulas
Energy (kWh) = Power (kW) × Load factor × Hours
Cost = Energy × Tariff
Cost = Energy × Tariff
Worked example
A 7.5 kW pump at 80 % load, 16 h/day for 330 days at 9 per kWh uses 96 kWh/day and costs about 285,120 per year.
Key insight: a VFD on a centrifugal pump or fan running at 80 % speed needs only about half the power, so energy cost is often the strongest case for adding a drive.
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Frequently Asked Questions
How do I calculate kWh?
Multiply power in kW by the hours of use. A 2 kW heater for 3 hours uses 6 kWh.
What is load factor?
The average fraction of rated power the equipment actually draws. Motors rarely run at full nameplate power.
Does this include maximum demand charges?
No. It covers energy (kWh) charges only; check your tariff for demand and power factor charges.
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