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Inverter VA & Wattage Size Calculator for Home

Calculate the total running wattage and power factor surge requirements of your household devices to pick the ideal inverter (650VA, 900VA, 1100VA, 1500VA, 2000VA+).

Recommended Inverter Size
650 VA (12V)

Ideal for 1-2 BHK essential lights & fans

Total Running Load:358 Watts
Calculated VA:560 VA
Battery Setup:1 Battery (12V)
Calculated with 25% surge safety margin

Select Appliances You Want to Run During Power Cut

BLDC Ceiling Fan

30W each · 60W total
2

Standard Ceiling Fan

75W each · 75W total
1

LED Bulb (9W)

9W each · 36W total
4

LED Tube Light (20W)

20W each · 40W total
2

Smart LED TV 43"

70W each · 70W total
1

WiFi Router + ONT

12W each · 12W total
1

Laptop Charging

65W each · 65W total
1

Inverter Refrigerator (250L)

180W each
0

Desert Air Cooler

160W each
0

CCTV Setup (4 Ch + DVR)

40W each
0

Water Pump (0.5 HP)

375W each
0

1.5 Ton 5-Star Inverter AC

1200W each
0

Advanced Settings & Power Factor

Inverter Power Factor (PF)0.8

Standard Indian inverters have 0.8 PF (Square wave/Modified) to 0.9 PF (Pure Sine Wave).

Safety Headroom Margin+25%

Provides headroom for motor starting surge (fan/fridge) to prevent overload trips.

How This Calculation Works & Technical Formula

Total Watts = Sum of all appliance wattages. Recommended Inverter VA = (Total Running Watts / 0.8 Power Factor) × 1.25 (Safety Headroom).

How to use this tool:

  1. Enter the quantity of each appliance you wish to run during a power cut.
  2. Adjust individual wattages if you use high-efficiency devices like BLDC fans or inverter ACs.
  3. View your total running wattage, peak surge wattage, and recommended inverter capacity.
  4. Check recommended commercial models (e.g. 900VA, 1100VA, 1500VA, or 2kVA).

Frequently Asked Questions

What is the difference between Inverter Watts and VA?+

Watts (W) measures the actual real power consumed by your appliances, whereas Volt-Amperes (VA) measures the apparent power supplied by the inverter. Because most electrical appliances have an inductive power factor (typically 0.8 in India), a 1000VA inverter supports approximately 800 Watts of load.

Why should I add a 25% safety margin when choosing an inverter?+

Motorized appliances like refrigerators, water pumps, and ceiling fans require 2x to 3x their running current for 1-2 seconds when starting up. The 25% headroom prevents the inverter from tripping and increases its operational lifespan.

Can an inverter run a refrigerator or microwave?+

Yes, modern pure sine wave inverters of 1100VA and above can easily run an inverter refrigerator (150W-250W). For microwaves or water pumps, an inverter of at least 1500VA to 2000VA (usually 24V double battery) is recommended.

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