Wire Size Calculator — Find the Correct Wire for AC, Geyser, Motor & Lighting
Pick the appliance, get the recommended copper / aluminium wire size in sqmm and the suitable MCB rating. Built for Indian 230V single-phase homes and small offices. Tool follows IS 732 + standard practice.
Calculator
Standard wire-size chart (Indian homes, 230V)
| Wire size (sqmm) | Max current (A) | Max load @ 230V | Typical use |
|---|---|---|---|
| 1.0 | 11 A | ~2.5 kW | Lighting circuits, fan circuits |
| 1.5 | 13 A | ~3.0 kW | Lighting + 5A sockets, small fan circuits |
| 2.5 | 20 A | ~4.6 kW | 16A power sockets, 1-1.5 ton AC, 2 kW geyser |
| 4.0 | 26 A | ~6.0 kW | 2 ton AC, 3 kW instant geyser, kitchen circuit |
| 6.0 | 34 A | ~7.8 kW | EV charger, large kitchen, 2 HP motor |
| 10.0 | 46 A | ~10.5 kW | Service mains, large workshop circuits |
| 16.0 | 62 A | ~14.3 kW | Service mains, three-phase distribution |
Values for copper conductor at 30°C ambient, single-phase, conduit-installed. Aluminium needs one size larger for the same load. Always use a qualified electrician for installation.
Frequently asked
Copper or aluminium — which is better?
Copper is preferred for indoor wiring (better conductivity, more durable connections, lower resistance). Aluminium is fine for service lines and long external runs where weight and cost matter, but use one size larger for the same load.
Which brand of wire is best in India?
For Chennai we recommend Polycab, Finolex and Havells — all ISI-marked, FRLS-rated, available in 90 mtr coils and project packing. See our wire dealer page for Sowcarpet.
Do I need FR or FRLS wire?
FR (Flame Retardant) is the minimum standard. FRLS (Flame Retardant Low Smoke) costs ~10% more but releases far less smoke during a fire — recommended for kitchens, hotels, hospitals, and any concealed conduit run. Modern apartments increasingly mandate FRLS.
What is voltage drop and when does it matter?
Long cable runs cause voltage to drop along the wire. For runs over 15 metres, step up to the next size. Our calculator already factors in run length above.
Need wire delivered today?
Polycab, Finolex, Havells in Chennai — same-day Sowcarpet delivery, next-day across Chennai. WhatsApp your size + length for instant quote.