About
About Solar Panel Cost Calculator
Solar Panel Cost Calculator is an independent educational planning site for estimating solar panel output, project cost, electricity bill savings, payback period, panel count and long-term return.
The site is designed for early research before requesting installer quotes. It does not sell solar systems, rank installers or provide personalised engineering advice. Instead, it exposes the main assumptions so users can test their own figures and understand why different solar proposals can produce different results.
What this site helps estimate
- Approximate daily, monthly and annual solar electricity production.
- How many panels may be needed for a target system size.
- Estimated annual bill savings from self-used solar electricity.
- Estimated export earnings where surplus solar can be sold or credited.
- Simple payback period and long-term solar ROI.
- How battery storage can change self-consumption assumptions.
Our editorial approach
Calculator assumptions are deliberately visible rather than hidden behind a single headline result. Users can change system size, peak sun hours, performance ratio, electricity price, export tariff, installed cost, panel wattage, self-consumption and degradation. The methodology page documents the formulas used by the calculators, while the data sources page explains where users can obtain reliable local inputs.
Content is written to help users understand solar economics rather than to promote a particular installer, manufacturer or product. Example costs and production figures are labelled as planning examples, because real installation prices, incentives, grid rules and tariffs vary by location and change over time.
How content is reviewed
When the calculator logic or supporting guidance changes, the relevant methodology, data-source and explanatory pages are reviewed for consistency. Pages that discuss country-specific assumptions are written to direct users toward their current local utility, government, regulator or solar-resource source rather than presenting a generic figure as universally correct.
We avoid presenting installer quotes, incentive eligibility or future electricity prices as guaranteed facts. Where a value depends on the user’s location or tariff, the calculator requires the user to enter or verify that value. This makes the estimate more transparent and reduces the risk of an outdated default being mistaken for a current local rate.
How to use the results
The results should be treated as planning estimates, not quotations, guarantees, engineering designs or financial advice. Solar outcomes vary with roof direction, roof pitch, shading, local weather, inverter efficiency, grid rules, retail electricity prices, export tariffs, installer pricing, financing and available incentives.
For a realistic decision, compare the calculator output with current installer proposals, your actual electricity tariff, your household usage pattern and any applicable permits or incentives. Run conservative and central scenarios rather than relying on one optimistic result.
Key assumptions to check
- Your average electricity import price per kWh.
- Your local feed-in, export or net-metering arrangement.
- Average peak sun hours for your region and roof.
- Roof orientation, pitch and shading.
- Installed cost and exactly what the quote includes.
- Whether optional battery storage is included in the project cost.
- Any financing cost, tax treatment or eligibility requirement that the simple calculator does not model automatically.
Corrections and contact
If you find an error, an outdated link or a calculation issue, use the contact page. Useful corrections include the page URL, the value or statement in question and a source that can be checked. This helps keep the calculators and supporting explanations consistent.