VA to Watts Calculator
Watts = VA × power factor. IPS and inverter sizes are printed in VA (e.g. 1000VA), but your appliances consume watts — so a 1000VA IPS delivers roughly 800W to a typical home load. Enter the VA rating below to see the real power it can supply.
Convert VA to watts
Enter a value above to see the result.
Common IPS sizes and what they run (power factor 0.8)
| IPS size | Real power | Typical load |
|---|---|---|
| 500VA | 400W | 2 fans + 4 LED bulbs + router |
| 650VA | 520W | 3 fans + 5 bulbs + TV + router |
| 1000VA | 800W | 3 fans + 5 bulbs + TV + router + 4 CCTV |
| 1500VA | 1200W | Above + refrigerator |
| 2000VA | 1600W | Above + water pump (running) |
Real power = VA × 0.8. These are typical-appliance examples — add your exact list in the IPS calculator. Fridges and pumps need surge headroom on top.
Worked example
A 650VA IPS delivers about 520W — enough for 3 fans, 5 LED bulbs and a TV. A 1500VA IPS delivers about 1200W, which comfortably covers a refrigerator running load on top. This is the single most useful number to know before buying an IPS.
Common mistakes
- Assuming VA = watts — a 1000VA IPS is not a 1000W IPS for typical loads.
- Buying an IPS that matches the load watts exactly, leaving no room for the power factor or starting surge.
- Ignoring surge: fridges, water pumps and ACs can need 3–4× their running power for a moment at startup.
Frequently asked questions
How many watts can a 1000VA IPS run?
About 800W of typical home load (1000 × 0.8 power factor). For purely resistive loads like bulbs and heaters it can reach closer to 1000W, but for motor loads like fridges and pumps you should stay under 800W — and still leave surge headroom for the moment they start.
What is power factor in simple words?
Power factor is the fraction of the electricity drawn that actually does useful work. Fans, fridges and ACs use about 70–90% usefully; bulbs and heaters use all of it. That's why a 1000VA IPS doesn't equal 1000W — the VA number describes the wiring load, not the usable power.
Should I buy an IPS by VA or by watts?
Use both. Add up the watts of everything you want to run on backup, then choose an IPS whose VA rating is at least your load divided by 0.8. For example, 600W of load needs roughly a 750–800VA IPS; most people then buy the next common size, 1000VA, for comfort and surge headroom.
Why is my recommended IPS bigger than my total load?
Three reasons: the power factor (the IPS's VA rating is always larger than its usable watts), a safety margin so the IPS isn't running at 100% all the time, and starting surge from fridges, pumps and ACs, which can briefly need 3–4× the running power.