Inverter Size Calculator
Calculate the exact Inverter VA rating and battery system voltage required for your household running wattage with safety headroom.
Start with a common home appliance setup
Select a scenario to fill running watts, then change the value to match your appliance nameplates. These are example loads, not guaranteed inverter capacity.
Running load used: 450 W. Estimated recommended inverter rating: 704 VA; check the selected manufacturer's continuous watt and surge ratings.
Absorbs motor starting surges and prevents MOSFET overheating.
Indian domestic appliance standard PF is 0.8 due to ceiling fan inductive coils.
Pure Sine Wave is essential for modern Indian homes to prevent ceiling fan humming, protect SMPS laptop/phone chargers, and safely run refrigerator inverter boards.
Frequently Asked Questions
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Continue with another electricity or backup-planning tool.
Reference official efficiency and safety guidance from Bureau of Energy Efficiency and standards information from Bureau of Indian Standards.
Calculation Assumptions & Safety
Calculations are planning estimates using the displayed inputs and assumptions, not certified designs or verified provider bills. Actual runtime, generation, cost and wire requirements vary with equipment, installation and operating conditions. Confirm manufacturer specifications and current provider rules. Have a qualified electrician review wiring and backup installations.
Inverter size for 2 fans, 4 lights and a TV
Two 70 W fans, four 9 W LED lights and an 80 W TV use 256 W while running together. At an assumed power factor of 0.8 with 25% headroom, planning capacity is 256 ÷ 0.8 × 1.25 = 400 VA. Check continuous output watts and startup surge before buying.
How the calculation works
Planning VA = simultaneous running watts ÷ assumed power factor × headroom factor. Battery Ah determines runtime separately; a larger VA rating alone does not extend backup.
Compare household scenarios
- 2 fans + 4 LEDs + TV: 256 W, example 400 VA
- 3 fans + 6 LEDs + TV: 344 W, example 538 VA
- Add a refrigerator: use its actual nameplate and starting characteristics
Common questions
- What size inverter runs two fans and a TV?
- Add the real rated watts of both fans and the TV, then allow appropriate headroom and check inverter output ratings. Appliance counts alone cannot guarantee compatibility.
- Can a 900 VA inverter run a fridge?
- It depends on both continuous watt rating and refrigerator starting demand. Consult equipment specifications; do not size from VA alone.