How many kW of solar does your home need?
Enter your appliances and daily usage to get a quick estimate of your recommended solar system — panels, inverter size and battery backup.
Tell us about your property
Two quick questions, then we get to the appliances.
What are you calculating for?
How many people use this property?
Optional — it only helps us sanity-check your usage.
Do you want battery backup?
Batteries keep your home running during load shedding, but add a lot to the cost. If you are unsure, skip it — you can come back.
What do you use at home?
Start from a preset and edit it, or pick appliances one by one. You do not need to list everything — the big loads matter most.
Start from a preset
Or add appliances yourself
Nothing added yet
How much do you use each one?
Wattages are typical values — change any that you know. Every appliance is different, and the label on yours is more accurate than our guess.
Backup and panel choice
Last step. Then we work out your estimate.
Do you want battery backup?
How many hours of backup do you want?
What should keep running during a power cut?
Most people back up lights, fans and the fridge rather than the whole house — backing up an AC multiplies the battery cost.
Which panels will you use?
Panel wattage changes how many you need, not the system size.
0kW
Recommended solar system size, based on what you entered
Estimate prepared · tools.srwebx.com/solar-calculator
Battery: not included. This estimate assumes a grid-tied or hybrid system without battery backup.
How we worked this out
Your appliances
| Appliance | Qty | Watts | Hours | Daily kWh |
|---|---|---|---|---|
| Total estimated daily usage | ||||
Want a professional solar quotation?
This estimate is a starting point. A qualified installer can survey your roof, check your bills and design the real system.
Get in touchThis calculator provides an approximate solar system estimate based on the information you entered. Actual electricity consumption, appliance efficiency, solar irradiation, shading, roof orientation, inverter specifications, battery requirements and local conditions can affect the final system size. Always have the final design verified by a qualified solar professional before installation.
Free solar system calculator for Pakistani homes
Every solar quotation starts with one question: how many kilowatts do you actually need? Ask three companies and you can get three different answers, because the honest answer depends on what is running in your house and when. This calculator works it out from your own appliances rather than from a rule of thumb.
It is built around a distinction that cheap calculators skip. The number of panels you need depends on your energy use — the units you consume across a whole day. The inverter you need depends on your power demand — how much is switched on at the same moment. A house with a fridge and thirty light bulbs and a house with a kettle and two air conditioners can use similar units per day and need very different inverters.
How the calculation works
- Daily energy per appliance Quantity × watts × hours per day, divided by 1000, gives kilowatt-hours. Appliances that cycle on and off, like fridges and air conditioners, are counted at a fraction of their rated wattage, because a fridge plugged in for 24 hours is not drawing 200 W for 24 hours.
- Panel capacity Daily kWh divided by peak sun hours and system efficiency. We assume 5 peak sun hours and 80% efficiency, then add a 15% design margin so the system is not sized exactly at today's usage.
- Rounding The result is rounded up to a system size actually sold in Pakistan — 3 kW, 5 kW, 6 kW, 8 kW and so on.
- Panel count System watts divided by panel watts, always rounded up. Eleven 580 W panels for a 6 kW system, because you cannot buy a third of a panel.
- Inverter Sized from your maximum simultaneous load plus headroom for motor starting surges — never simply matched to the panel array.
- Battery Backup load × hours ÷ 80% usable depth, if you asked for backup.
What affects your real solar requirement
- Air conditioning. A single 1.5 ton unit can double a modest home's daily consumption. Nothing else on a typical bill comes close.
- Location and season. Sunlight in Pakistan varies by region and time of year — winter fog in central Punjab and the monsoon both cut generation well below the annual average.
- Roof space and orientation. A 10 kW array needs somewhere to sit. South-facing, unshaded roof space is what makes the difference between the estimate and reality.
- Shading. One tree or one neighbouring wall across part of the array costs more output than most people expect.
- Dust. Panels in Pakistan lose noticeable output between cleanings. That is part of why the efficiency assumption here is 80% rather than a lab figure.
- Net metering. If you export to the grid, the economics of a slightly larger system change considerably.
Frequently asked questions
How many kW solar system do I need for my home in Pakistan?
It depends on two separate things: the units of electricity you use in a day, which decides the panels, and how much you run at once, which decides the inverter. A typical home running lights, fans, a fridge and a TV usually lands between 3 kW and 6 kW. Add air conditioners and it climbs quickly to 10 kW or beyond. Rather than guessing, enter your actual appliances above.
How many solar panels do I need?
Divide the system size by the panel wattage and round up. A 6 kW system with 580 W panels needs 11 panels — 6000 ÷ 580 is 10.34, and you cannot buy a third of a panel. Higher-wattage panels mean fewer panels and less roof space for the same capacity.
Is a battery required for solar?
No. A grid-tied or hybrid system without batteries runs your home on solar during daylight and falls back to the grid at night — the cheapest way to cut a bill. Batteries are for keeping power during load shedding, and they add substantially to the cost. Many households start without batteries and add them later, provided the inverter supports it.
How many hours of sunlight does Pakistan get?
Most of the country receives roughly 4.5 to 5.5 usable peak sun hours a day averaged across the year — higher in Balochistan and southern Punjab, lower during the monsoon and winter fog. This calculator assumes 5 hours. That is an average, not a promise: a December week in Lahore will produce far less than a May week in Quetta.
Can I run an AC on solar?
Yes, but air conditioners are the heaviest load in most Pakistani homes. A 1.5 ton inverter AC averages roughly 1 to 1.2 kW while running, and the compressor draws a surge when it starts. Two of them need both a much larger array and an inverter rated to handle those surges — which is why the calculator sizes the inverter from your maximum load rather than from the panels.
Is this calculator 100% accurate?
No, and no calculator can be. It is an estimate built from the numbers you typed and a set of stated assumptions. It cannot see your roof, your shading, your wiring, your phase requirements or your actual electricity bills. Use it to understand roughly what size to ask about, then have a qualified installer survey the site before you spend anything.