Free Home Electrical Load Calculator (UK)
Modern homes use far more electricity than they did in the past. Appliances such as EV chargers, electric showers, induction hobs, heat pumps, and hot tubs place significant demand on a property's electrical system.
Many UK homes were originally designed when electrical demand was much lower, meaning new appliances can push installations close to their limits.
This free electrical load calculator helps estimate whether your home electrical supply may be approaching its capacity. It provides a general indication based on the appliances you select—not a precise engineering calculation.
Important: This calculator provides an estimate only. A qualified electrician should confirm electrical capacity before installing high-power appliances.
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Call Amerson Electrical: 0131 358 9935Estimate Your Home Electrical Load
Your Appliances
How Much Electrical Load Can a UK House Handle?
Every UK home has a main fuse (also called a cut-out or service head) that limits the maximum current the property can draw from the electricity network. This is typically rated at 60, 80, or 100 amps.
The table below shows the approximate maximum power capacity for each supply rating, calculated using the standard UK voltage of 230 volts:
| Supply Rating | Approx Power Capacity |
|---|---|
| 60A | ~13.8kW |
| 80A | ~18.4kW |
| 100A | ~23kW |
However, the maximum supply rating doesn't tell the whole story. Electricians apply diversity calculations when assessing electrical capacity because not all appliances operate simultaneously or at full power.
For example, you wouldn't run your oven, hob, shower, tumble dryer, and EV charger all at the same time. Diversity factors account for realistic usage patterns, typically reducing the estimated maximum demand to around 60-70% of the total connected load.
Older properties, particularly those built before 1980, may have 60A supplies that were adequate for their original purpose but struggle with modern electrical demands. If you're planning to install an EV charger, heat pump, or other high-power appliance, it's worth checking your supply capacity first.
Typical Electrical Loads of Common Appliances
Understanding how much power your appliances draw helps you estimate whether your electrical system can cope with additional loads. Here are typical power ratings for common high-demand appliances:
| Appliance | Typical Power |
|---|---|
| EV Charger (7kW) | 7.2kW |
| Electric Shower | 8–10kW |
| Induction Hob | 5–7kW |
| Electric Oven | 2–4kW |
| Tumble Dryer | 2–3kW |
| Heat Pump | 2–5kW |
| Hot Tub | 3–6kW |
| Immersion Heater | 3kW |
Note: Actual power consumption varies by make and model. Check the rating plate on your appliances for precise figures.
Signs Your Electrical System May Be Near Capacity
If you're experiencing any of the following, your electrical system may be struggling to meet demand:
Circuit breakers frequently tripping
Lights dimming when appliances start
Installing an EV charger or electric shower
Older fuse boards or consumer units
Limited spare circuits available
Multiple high-power appliances running simultaneously
Experiencing these issues? Get professional advice.
Call 0131 358 9935Frequently Asked Questions
Disclaimer
This calculator provides an estimate only. Electrical capacity depends on wiring design, circuit protection, diversity calculations, cable sizing, and supply characteristics. The results should not be relied upon for design purposes or to determine whether your installation can support specific appliances. Always consult a qualified electrician before installing new high-power appliances.
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Electrical Work Price Calculator →Need a Professional Electrical Capacity Check?
Amerson Electrical can inspect your home's electrical supply before installing EV chargers, electric showers, heat pumps, or other high-power appliances. We'll assess your current capacity and advise on any upgrades required.