Electrical Load Calculator — Domestic Property
Calculate the total electrical load for a UK domestic property. Enter the number of each appliance to see the total connected load and estimated maximum demand with diversity.
Enter quantity of each appliance
How We Calculate This
This calculator lists common UK domestic appliances with their typical wattage ratings. You enter the quantity of each appliance in your property, and the calculator determines both the total connected load and the estimated maximum demand using diversity factors.
The calculation
Connected Load = Sum of (quantity × rated watts) for all appliances
Maximum Demand = Sum of (connected load × diversity factor) for all appliances
Current (Amps) = Watts ÷ 230V
Typical appliance wattages
- Kettle: 3,000W (diversity 10% — intermittent use)
- Oven: 3,000W (diversity 60% — not always at full power)
- Electric Hob: 6,000W (diversity 50% — rarely all rings at full)
- Washing Machine: 2,500W (diversity 30%)
- Electric Shower: 8,500-10,500W (diversity 100% — full load when on)
- Immersion Heater: 3,000W (diversity 100%)
- EV Charger: 3,600-7,000W (diversity 100% — continuous load)
The diversity factors used are based on typical domestic usage patterns and BS 7671 Table 1B guidance. Actual usage may vary — this provides a reasonable estimate for supply sizing purposes.
Frequently Asked Questions
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Last updated: February 2026
All calculations are estimates. Verify with your supplier.