Calculate the right solar system for your home
Use this solar calculator for a starting estimate based on your monthly bill and backup priorities. We'll suggest a package and rough savings range, then a free quote confirms the detail.
Compare subscription, rent-to-own and buying
Add up every increase, fee and buyout over the years you expect to stay, and see what each route really costs.
Score and compare your solar quotes
Check up to three quotes against 15 items a complete quote should state, and get the questions to send about anything missing.
How many solar panels fit on your roof?
Lay out real panel sizes on each roof face and see the system size and yearly output for your city and roof direction.
Use the commercial project screening calculator
Screen the bill, operating hours, location, property control, daytime load and funding route before commissioning a design.
R2 000/month
Your suggested starting point
The Big Watt
R1,500–R3,000/month · Solar + battery
- Solis 5 kW inverter
- Eenovance 5.32 kWh battery
- 4 × 615 W panels
- 7-year rent-to-own
- R1 487/mo
- Initiation fee
- R738
- Est. monthly saving
- R728
- Buyout after 7 years
- R7 378
- Buy outright from
- R73 779
- Estimated backup
- Up to 3 hrs
This is an indicative starting point. The site assessment and signed quote confirm the system, current price, equipment, savings and backup time. Rent-to-own payments increase by 6.5% each year.
What this solar calculator estimates
Your bill and backup priority point to a starting system size, panel count, battery range and package route.
What it cannot confirm
A calculator cannot see your roof, wiring, shade, phase supply or exact appliance loads. A site assessment confirms the design.
Ready for a real quote?
Send the result with your enquiry so the provider can start with the information you have already supplied.
This tool gives a rough, indicative starting point only — it is not a quote. The right system depends on your actual usage pattern, roof, appliances and budget, which a free site assessment confirms. SolarGuide is an independent referral partner; Alumo supplies, installs, finances and warrants the systems, and all pricing is subject to a site assessment and credit approval.
Use this tool on your own site
Journalists, bloggers and installers are welcome to quote or embed this tool free of charge. We only ask for a link back to the original so readers can check the working.
Figures, charts and calculator outputs on this page may be reproduced, in whole or in part, with clear attribution and a link to https://www.solarguide.co.za/calculator/. Last reviewed 3 September 2026. If you need a specific cut of the underlying assumptions for a story, email [email protected].
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