Currency: USD
Enter all amounts in USD. Changing currency keeps numbers unchanged; no exchange rate is applied.
- Energy used
- 120 kWh
- Energy charge
- $19.20
How it works
Avoid applying the load factor twice
If measured average power is already 400 W for a 1,000 W appliance, enter 400 W at full load or 1,000 W at 40%. Entering 400 W and 40% understates modeled energy by applying the adjustment twice.
Estimating energy use from power and time
An appliance drawing 1,500 watts uses 1.5 kW. Running at that power for 4 hours per day over 30 days consumes 1.5 × 4 × 30 = 180 kWh. At an entered price of 0.20 per kWh, the energy cost is 36 in the selected currency. Watts describe power; kilowatt-hours describe energy used over time. Use realistic running time or average draw for equipment that cycles on and off. Fixed charges and unentered tariff tiers are not included.
Electricity cost: formula and assumptions
Energy = power(W)/1000×hours×days. Cost = kWh×unit price.
This estimates energy charges, excluding fixed fees, demand charges, and tiered tariffs.
Usage with load factor: formula and assumptions
Energy = rated watts/1000×load factor×operating hours.
A load factor estimates average power relative to rated power; it does not change the hours entered.
Worked example
Reference example currency: USD. These fixed examples do not change with your calculator preferences.
Using the Electricity cost example:
- Power (W)
- 1000
- Hours used per day
- 4
- Days
- 30
- Electricity price ($/kWh)
- 0.16
Energy = power(W)/1000×hours×days. Cost = kWh×unit price.
Example result
Energy used: 120 kWh
Energy charge: $19.20
These are illustrative inputs. Change the values to explore a different scenario.
Formula references
References explain the underlying methods; they do not imply endorsement or individual professional review of Finflo.
Common questions
How do watts differ from kilowatt-hours?
Watts describe power at a moment. Kilowatt-hours measure energy used over time: kilowatts multiplied by operating hours.
Will the result match my entire electricity bill?
No. It estimates energy charges and excludes fixed fees, demand charges, tiered tariffs and other account-specific charges.
Prepared by Finflo. See our methodology and editorial policy.