Solar panel cost calculator
Estimate your upfront cost, annual saving and payback — instantly, with no email and no sales call. Drag the sliders to match your home.
Estimate your solar costs
~3400 kWh generated a year
Refine assumptions
Upfront cost
£7,000
Annual saving
£629
Payback
11.1 yrs
Estimate only — assumptions as of June 2026. Not financial advice. Actual costs depend on your roof, tariff and quotes.
Get a real quote from an MCS-certified installer in South YorkshireHow the calculator works
- Set your system size. Slide to your planned kW (4kW suits most 2–3 bed homes).
- Enter your annual electricity use. Find it on your bill in kWh; the UK average is ~2,700–3,500 kWh.
- Add a battery if relevant. A battery raises self-consumption and adds roughly £5,000.
- Read your result. See estimated upfront cost, annual saving and payback instantly — no email required.
It multiplies your system size by ~850 kWh per kWp to estimate annual generation, splits that into energy you use directly (≈35%, or ≈70% with a battery) versus exported surplus, then values each at your electricity price and SEG export rate. Upfront cost is interpolated from typical UK installed prices.
How many panels do I need?
As a rule of thumb: a 2–3 bed home needs ~8–10 panels (3.5–4kW); a 4–5 bed home or one with an EV/heat pump needs ~12–18 panels (5–8kW). For the price behind each size, see cost of solar panels by size, and for the maths behind the payback figure, see the payback method.
Our assumptions
This is a planning estimate, not a quote. We model ~25p/kWh import and ~15p/kWh SEG export (June 2026), 0% VAT, and ~850 kWh per kWp annual yield. Real figures depend on your roof orientation, shading, tariff and installer. We publish every assumption and the date it was set, and we take no commission on any quote.
Frequently asked questions
How many solar panels do I need for my home?
A 2–3 bedroom home usually needs a 3.5–4kW system — about 8–10 panels. Homes with an EV or heat pump often go to 5–6kW (12–15 panels). Roof space and orientation set the practical limit.
Is this calculator free and does it need my email?
Yes, it is completely free and asks for no email or contact details. Every supplier "free quote" tool we tested gated the result behind your phone number; this one does not.
How accurate is the estimate?
It uses typical UK installed prices and generation (~850 kWh per kWp/year) plus your tariff inputs. It is an estimate for planning only — your real cost depends on your roof, shading and quotes. Assumptions are published and dated.