Solar Calculator Pakistan — Estimate Your Home Solar System in Minutes
Find out exactly how many kilowatts of solar your home needs, your estimated monthly savings, and your environmental impact — free, and without uploading a single bill. Just pick your appliances and get an instant system size, savings breakdown, and CO₂ impact tailored for Pakistani homes.
Raj Solar · Free Estimate
Home Solar System Calculator
Pick the appliances in your home and find out in seconds how many kilowatts of solar you need, how much you'll save every month, and your impact on the environment. Built on real Pakistani usage numbers — no bill upload required.
What's in your home?
Set the quantity and daily usage hours. Defaults are already realistic.
How This Calculator Sizes Your Solar System
This tool runs the same sizing formula we use on-site. You select your appliances, and the calculator multiplies wattage by daily hours to get your total load in kilowatt-hours. It then divides that by your city's peak sun hours and applies a 0.78 derate — that factor covers real losses: inverter efficiency, wiring, panel heat, and Karachi-level dust buildup between washes.
The result is your estimated system size in kW. We round up to the next standard size that's actually available in the market — 3, 5, 6, 8, 10, 12, 15 or 20 kW. Nobody manufactures a 7.4 kW inverter. That's why we size every solar installation to standard market configurations. You'll get an 8 kW, and the extra headroom helps on cloudy days. For reference, a 5 kW solar system in Pakistan uses 8 panels of 650W and a 5 kW inverter.
City selection changes the result more than people expect. Karachi and Multan get about 4.9 peak sun hours. Lahore and Faisalabad sit around 4.6. Islamabad drops to 4.5. Quetta leads at 5.2. We've seen the same household load need a 6 kW array in Islamabad that a 5 kW covers in Karachi — those 0.4 extra sun hours add up across a full year.
Worked Example — A Typical Karachi Home
A home in DHA Karachi. 1 inverter AC (1.5 ton, 6 hrs), 4 ceiling fans running 12 hours, a fridge, washing machine, 8 LED bulbs, TV, and WiFi router. Calculator totals this at 16.9 kWh/day.
Divide by 4.9 sun hours × 0.78 derate = 4.4 kW estimated. Next market size up: 5 kW.
This is close to what we installed for a client in Clifton — a 6 kW hybrid with battery backup. Actual generation matched the estimate within 12%. A 5 kW on-grid solar system in Karachi generates 600 to 900 units per month and saves approximately PKR 33,000 at current tariffs.
What Size Solar System Does Your Home Need?
If you know your monthly bill, this table gives a quick starting point. The calculator above is more precise — it accounts for your actual appliances, city, and system type. But across 150+ installations, these ranges hold for most homes.
| Monthly Bill (PKR) | Approx. Units | System Size |
|---|---|---|
| 10,000 – 20,000 | 150 – 350 units | 3 – 4 kW |
| 20,000 – 35,000 | 350 – 600 units | 5 – 6 kW |
| 35,000 – 55,000 | 600 – 900 units | 8 – 10 kW |
| 55,000 – 80,000 | 900 – 1,300 units | 10 – 12 kW |
| 80,000+ | 1,300+ units | 15 – 20 kW |
These assume on-grid with Tier-1 panels — Longi, Jinko, JA Solar, Canadian Solar, or Trina. Final sizing depends on your roof. RCC slab is straightforward. Tin or sheet roofing needs additional racking. Shading from a neighbor's building or a water tank can knock out a panel row entirely — that's something we check during the free site visit before quoting. A 10 kW solar system needs 550 to 650 square feet of shade-free roof space with 650W panels. A 10 kW solar system needs 550 to 650 square feet of shade-free roof space with 650W panels. Explore our full range of solar services to see what's included.
On-Grid vs Hybrid vs Off-Grid — Which One Fits?
The calculator asks for system type because it changes everything — panel count, inverter rating, battery requirement, and cost. Here's the real difference:
On-Grid
Lowest CostGrid-tied via net metering. No battery. Surplus goes to K-Electric or your DISCO for bill credit.
- Cheapest to install — no battery cost
- Fastest payback: 4–5 years
- Shuts off during load-shedding — that's an inverter safety requirement, not a flaw
- Best if your area gets stable supply
Hybrid
Most Popular in 2026Grid-connected plus battery. Stores daytime solar for evening use. Power stays on during outages. See how this works in our hybrid project gallery.
- Uninterrupted power during load-shedding
- Use your own solar at night instead of buying expensive peak-hour units
- Less export to grid — matters a lot under the new net billing rates
- Higher upfront cost, but significantly more independence
Off-Grid
Full IndependenceNo grid connection. 100% solar and battery. Needs a bigger array and battery bank.
- Zero dependence on K-Electric or any DISCO
- Needs 30% more panels and a large battery bank
- Highest upfront investment
- Makes sense where the grid is unavailable or drops out daily
For most homes in Karachi, Lahore, and Islamabad, hybrid is the right call in 2026. The economics have shifted. Under the new net billing policy, exporting surplus earns you roughly Rs 8–11/unit while importing costs Rs 35–65/unit depending on your slab. Storing generation in a battery and using it at peak hours saves three to five times more than exporting. That's why the majority of our recent installations have been hybrid. The solar payback period in Pakistan in 2026 is 5 to 7 years under net billing and 3 to 4 years under older net metering agreements.
Solar Savings After Net Billing 2026
On February 9, 2026, NEPRA replaced net metering with net billing under the Prosumer Regulations 2026. This is the biggest policy change for rooftop solar in Pakistan in a decade.
Export Rate: Before vs After
(before Feb 2026) PKR 35–65/unit 1:1 unit swap at your retail slab rate
(Feb 2026 onwards) ~PKR 8–11/unit NEPRA buyback rate (NAPPP-based)
The bottom line: every unit you use yourself during the day still saves you the full retail rate — Rs 35 to 65 depending on your slab. But every unit you export now earns roughly Rs 8–11. That's a 5-to-1 gap. Under NEPRA's 2026 net billing policy, solar exports earn roughly Rs 8 to 11 per unit while self-consumed units save Rs 35 to 65 at retail rates. Overproducing for export no longer makes financial sense.
Our recommendation for new installations: Size the system around your realistic daytime load, not your total bill. Add a battery if you can — even a 5 kWh lithium pack lets you shift morning solar to evening peak hours instead of exporting at Rs 8–11. Payback has moved from 3–4 years under the old policy to roughly 5–7 years under net billing. Still solid at current tariffs above PKR 40/unit. After payback, you get 18–20 years of near-free electricity.
If you had net metering approved before February 8, 2026, your existing agreement continues at the old rates until your contract expires. New applications fall under net billing. Confirm the current buyback rate with your DISCO — NEPRA reviews it periodically.
About Raj Solar
Raj Solar is a Karachi-based solar installation company with 210+ completed projects and 5,300+ kWp installed across residential and commercial sites in Pakistan. We provide end-to-end solar solutions — system design, installation, net metering applications, and after-sales support. This calculator is built and maintained by our engineering team based on real project data.Learn more about Raj Solar →
Frequently asked questions
How many kW solar system do I need for my home?
Most Pakistani homes need a 5 to 10 kW system. A smaller home with fans, lights, and a fridge sits around 3–5 kW. Add one or two inverter ACs and you're looking at 6–10 kW. The calculator above sizes it from your actual appliances — that's more reliable than guessing from your bill, because bills include fixed charges and taxes that inflate the number.
What's the difference between on-grid, hybrid and off-grid?
On-grid is the cheapest — it feeds surplus to the grid via net metering but shuts off during load-shedding. Hybrid adds a battery, so your power stays on during outages and you can use daytime solar at night. Off-grid has no grid connection at all — fully independent, but needs 30% more panels and a large battery bank. In 2026, we're recommending hybrid for most homes because it pairs better with the new net billing economics. Try switching between the three in the calculator above — you'll see how it changes your panel count, battery size, and savings.
How much can I save every month with solar?
A 5 kW system in Karachi saves roughly PKR 25,000–35,000 per month at current tariffs. A 10 kW system can offset PKR 55,000–75,000. These numbers depend on your tariff slab, daily usage pattern, and how much you self-consume vs export. The calculator gives you a personalized estimate based on your own appliances and the electricity rate you enter.
Do I have to upload my electricity bill?
No. The calculator sizes your system from appliances alone — no bill upload, no account number, no personal data. If you do enter last month's units, the estimate gets more accurate because it cross-checks your actual consumption against the appliance calculation. Either way works.
How long does a solar installation take?
1 to 3 days for a typical home, depending on system size and roof type. RCC slab is fastest. After installation, net metering approval from your DISCO — K-Electric in Karachi, LESCO in Lahore, IESCO in Islamabad — takes another 4 to 8 weeks. We handle the full application process.
Is solar worth it in Pakistan in 2026?
Yes — payback is 5 to 7 years under the new net billing policy at electricity rates above PKR 40/unit. After payback, your panels keep generating near-free electricity for 18–20 more years. That's a net positive of 13–15 years of savings. If you're on an older net metering agreement, payback is even faster at 3–4 years.
How accurate is this solar calculator?
Within 10–15% of a final engineered design. The calculator uses the same sizing formula our team applies during site assessments — real sun-hour data per city (Karachi 4.9, Lahore 4.6, Islamabad 4.5), a 0.78 derate factor for Pakistani conditions, and actual appliance wattages. The final system is confirmed after a free site visit where we check roof area, shading, and wiring.
How much roof space do I need for solar panels?
About 55–65 sq ft of shade-free roof per kW with 650W panels. A 5 kW system needs roughly 280–320 sq ft. A 10 kW system needs 550–650 sq ft. If your roof is tight, higher-wattage panels reduce the footprint. Water tanks, staircase sheds, and neighboring buildings are the usual blockers — our team maps it out during the site survey.
Do I need batteries with my solar system?
Only if you want load-shedding backup or nighttime solar use. A grid-tied on-grid system saves money without batteries. But in 2026, batteries make more financial sense than before — the net billing export rate dropped to roughly Rs 8–11/unit, while self-consuming a stored unit saves you Rs 35–65. Storing beats exporting by 3x to 5x. Select Hybrid in the calculator above to see your recommended battery size in kWh.
What is the payback period for solar in Pakistan?
5 to 7 years under net billing (February 2026 onwards). Homes on older net metering agreements see payback in 3 to 4 years. The bigger your bill, the faster the payback — every self-consumed unit avoids an expensive grid unit at Rs 35–65. Run your appliances in the calculator to see your estimated monthly saving — that's the number that drives your payback.