engineering Calculator

Power Consumption Calculator

Calculate energy usage in kWh and total operating electricity costs over daily, monthly, and annual cycles.

Audited by UniqCalc Methodology Team • Formula Checked • Free & No Registration Required

Verified Mathematical Model & Formulation

Energy (kWh) = (Power (Watts) × Operating Hours) / 1,000
Cost ($) = Energy (kWh) × Utility Rate ($/kWh)

Converts continuous electrical wattage into kilowatt-hours (kWh), the standard billing unit of global utility companies, and computes financial operating costs.

Configurable Parameters & Standard Units

  • Appliance Power (Watts): (Default: 1500 w)
  • Usage Hours per Day: (Default: 4 hours)
  • Electricity Cost ($/kWh): (Default: 0.16 usd)

Standard Worked Example & Practical Verification

Scenario: Running a 180W continuous home laboratory server 24/7 at $0.15 per kWh.

Calculated Solution
131.8 kWh/month ($19.76/month or $237/year)

Practical Takeaway: Idle continuous draw represents substantial recurring cost over multiple years.

Frequently Asked Questions

How do you find the wattage of an appliance?

Check the UL label on the back or bottom of the device. If only Volts (V) and Amps (A) are listed, multiply Volts × Amps = Watts.