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Kilowatt-Hour (kWh) Calculator

Convert electrical power and operating hours into kilowatt-hours (kWh) and megawatt-hours (MWh).

1. Enter your numbers  →  2. Check the answer  →  3. Read the steps before you trust it

W
hrs
days

Kilowatt-Hour Calculations

Total Energy Consumed
270 kWh

270,000 Watt-hours

Daily Energy
9 kWh/day
Monthly Energy (30 days)
270 kWh/mo
Annual Projection (365 days)
3,285 kWh/yr

Step-by-Step Engineering Calculation

  1. 1Total Energy: 1500 W×6 h×30 days1000=270.000 kWh\frac{1500\text{ W} \times 6\text{ h} \times 30\text{ days}}{1000} = \mathbf{270.000\text{ kWh}} (270000 Wh)
  2. 2Standard Daily Rate (6 h/day): 9.000 kWh9.000\text{ kWh}
  3. 3Standard Monthly Projection (30 days): 270.00 kWh270.00\text{ kWh}
  4. 4Standard Annual Projection (365 days): 3285.00 kWh3285.00\text{ kWh}

Formula & Theory

kWh = (Watts × Hours × Days) / 1000

Computes total electrical energy consumption in kilowatt-hours.

Variable Definitions
P:
Power (Watts (W) / kW) – Equipment operating wattage
T:
Time (Hours) – Operating duration
E:
Energy (Kilowatt-hours (kWh)) – Total energy consumed

Worked Engineering Example

Central AC System

A 3,500W air conditioner running 8 hours per day for 30 days.

Inputs:
  • Power: 3500 W
  • Hours: 8 h/day
  • Days: 30 days
Result: Total Energy = 840.00 kWh (840,000 Wh)

Key Assumptions

  • •Steady power consumption across operating period.

Limitations & Safety Scope

  • •Does not include power factor derating for VA billing.

Frequently Asked Questions

What is 1 kWh?

One kilowatt-hour (kWh) is the amount of electrical energy consumed by a 1,000-Watt appliance running continuously for 1 hour.

Related Calculators & Engineering Tools

Energy Cost Calculator
Power Calculator

Educational & Reference Notice: This calculator provides technical estimates based on standard physical formulas. Actual electrical installation, protective device sizing, and conductor selection must be verified against the applicable electrical code (NEC, IEC, CEC) by a licensed electrician or qualified professional engineer.