Wire Size Calculator
Enter an appliance load and get the recommended copper house-wiring cable size in sq mm, using conservative Indian sizing for 230 V single-phase circuits.
What size wire for a 2000 W appliance?
At 230 V a 2000 W load draws about 8.7 A, which 1.5 sq mm copper can carry. But for a socket that may later run a heater, 2.5 sq mm is the safer standard choice.
Guidance only, for copper conductor in conduit. Confirm final sizing with a licensed electrician.
How this works
The calculator converts your load to current (Amps = Watts ÷ Voltage) and matches it to a copper cable that can safely carry it with headroom to spare. Typical picks: 1.5 sq mm for lighting, 2.5 sq mm for power sockets, 4 sq mm for air conditioners and geysers, and 6 sq mm for very high loads or long runs.
How wire sizing works
Every cable can carry only so much current before it overheats, so the breaker and the wire must be matched to the load. The calculator converts your load to current using Amps = Watts ÷ Voltage (230 V single phase), then picks the smallest copper cable that carries it with safe headroom. Undersized wire is the single most common cause of overheating and insulation damage in Indian homes.
Two things cut a cable's real-world capacity: long runs (voltage drop) and bunching several cables in one conduit. For runs over about 15 m, or crowded conduits, step up one size.
Standard circuits in an Indian home
Most homes follow a simple pattern:
- 1.5 sq mm — lighting and fan circuits
- 2.5 sq mm — general 5A/15A power sockets
- 4 sq mm — air conditioners and geysers, on their own MCB
- 6 sq mm — very high loads or long runs
Always use ISI-marked (IS 694) copper wire, and give ACs and geysers a dedicated circuit.
| Copper cable | Carries (approx) | Typical use | MCB |
|---|---|---|---|
| 1.0 sq mm | 11 A | Lighting points | 6 A |
| 1.5 sq mm | 15 A | Lighting & fan circuits | 6-10 A |
| 2.5 sq mm | 20 A | Power sockets, fridge, TV | 16 A |
| 4 sq mm | 28 A | AC, geyser (dedicated) | 20 A |
| 6 sq mm | 36 A | Large AC, long runs | 25-32 A |
| 10 sq mm | 50 A | Sub-mains | 40 A |
Frequently asked questions
What size wire for a 2000 W appliance?
At 230 V a 2000 W load draws about 8.7 A, which 1.5 sq mm copper can carry. But for a socket that may later run a heater, 2.5 sq mm is the safer standard choice.
Copper or aluminium wire?
Use copper for internal house wiring. It carries roughly 60% more current per sq mm and tolerates a slightly loose terminal without overheating, unlike aluminium.
Does cable length change the size?
Yes. Long runs lose voltage, so a 25 m run to a geyser may need one size up (6 sq mm instead of 4) to keep the voltage healthy at the appliance.
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