The formula
Maximum watts = Amps × Volts
UK 16 A × 230 V = 3,680 W US 30 A × 120 V = 3,600 W
Typical loads
| Appliance | Typical watts |
|---|---|
| Kettle (domestic) | 2,000–3,000 W |
| Low-wattage camping kettle | 750–1,000 W |
| Hair dryer | 1,000–2,000 W |
| Microwave (input) | 1,000–1,300 W |
| Electric heater | 500–2,000 W |
| Battery charger 40 A at 12 V | ~650 W |
| RV air conditioner (13,500 BTU) | 1,200–1,600 W running |
Tips
- Many UK sites offer only 6 A or 10 A. A 2 kW kettle plus a heater will trip a 10 A supply.
- Uncoil cable reels fully. A coiled reel can overheat at high current.
- For a 50 A RV service the 12,000 W is split across two 120 V legs of 6,000 W each, so balance big loads between them.
Frequently asked questions
How many watts is a 16 amp hook-up?
16 A × 230 V = 3,680 W. In practice keep continuous loads below about 3,000 W.
Can I run a kettle on a 10 amp hook-up?
Yes, a standard 2–2.4 kW kettle is within 2,300 W on its own, but not with a heater or other big loads at the same time.
How many watts is 30 amp RV service?
30 A × 120 V = 3,600 W. A 50 A service provides 12,000 W split across two 120 V legs.