IPS Backup Calculator
Pick what you need to keep running during load shedding, choose how long, and we'll size the IPS and battery for you — the same maths our team uses on the phone, with 20% headroom and honest backup estimates. No guesswork, no oversized bills.
1 · What do you want to keep running?
2 · How many hours of backup?
Dhaka load shedding spells are usually 1–2 hours at a time; 4 hours covers several spells in a day without recharging.
Your recommendation
⚠️ Your fridge/motor needs a high surge to start its compressor — that sets the minimum IPS size, even if the running load looks small.
Assumes a pure sine wave IPS (85% efficient) and tubular batteries discharged to a battery-friendly 60% — deeper discharge shortens battery life. Estimates, not guarantees: real backup varies with battery age and charge.
Confirm with an expert — freeSizing questions people ask
How do I know what size IPS I need in Bangladesh?
Add up the running watts of everything you want to keep on — a ceiling fan is about 75W, an LED bulb 12W, a TV 100W, a fridge 180W — then add 20% headroom. That total decides the IPS capacity. This calculator does the arithmetic for you and names the matching model.
Why does a fridge need a bigger IPS than its running watts suggest?
A fridge or water pump draws a large surge for a moment when its compressor or motor starts — several times its running wattage. That surge, not the running load, sets the minimum size: we recommend at least 1000VA for a fridge and 1500VA for a ½HP pump.
How many hours of backup will I get?
Backup hours depend on the battery, not the IPS. The calculator estimates real hours using 85% inverter efficiency and a battery-friendly 60% depth of discharge, so the figure is what you should actually see — not a best-case number.
Is the battery included with an IPS?
No. In Bangladesh every IPS is sold without a battery so you can choose the capacity that matches your backup hours. The calculator tells you both the IPS size and the battery Ah to buy with it.
What size battery should I buy — 100Ah, 165Ah or 200Ah?
Bigger Ah means longer backup at the same load, not more appliances. A 165Ah tubular suits a typical family evening of fans, lights and a TV; go to 200Ah or 230Ah if you run a fridge or need to cover several outages a day.
Products That Match Your Numbers
Nothing in stock matches exactly — browse all IPS or ask us; we can usually source the right size within a few days.