Ohms to Kilowatt Hours Calculator
Enter resistance (ohms), voltage (V), and time (hours) to calculate energy consumption in kilowatt-hours.
Input Values
Resistance of the load in ohms
Supply voltage in volts
Duration the device is running
Your electricity cost per kWh for cost estimate
Enter values and click Calculate to see results
Current
Amperes (A) — via Ohm's Law: I = V / R
Power
Watts (W) — P = V² / R
Energy Consumption
Kilowatt-hours (kWh) — E = P × t / 1000
Estimated Cost
Based on your entered electricity rate
Formula Breakdown
Summary
Enter resistance (ohms), voltage (V), and time (hours) to calculate energy consumption in kilowatt-hours.
How it works
- Enter the resistance of your device in ohms (Ω).
- Enter the supply voltage in volts (V).
- Enter the duration the device runs in hours.
- The calculator derives current using Ohm's Law: I = V / R.
- Power is computed as P = V² / R, then energy as E = P × t / 1000.
- Results show power in watts and energy in kilowatt-hours (kWh).
Use cases
- Estimate electricity consumption for electric heaters and heating elements.
- Calculate energy cost for resistive loads in industrial equipment.
- Check power draw of a known resistance at a given voltage.
- Verify energy usage for DIY electronics projects.
- Compare energy consumption across different operating voltages.
- Estimate monthly electricity bills for appliances with known resistance.
Frequently Asked Questions
Last updated: 2026-06-14 ·
Reviewed by Nham Vu