About SolarMath
A free, no-bs solar calculator built for Australians who want realistic numbers — not sales pitches.
Why this exists
Most solar calculators are built by companies trying to sell you something. They use optimistic assumptions, ignore hidden costs, and conveniently forget that batteries don't always make financial sense.
SolarMath is different. We're not affiliated with any solar installers, don't sell leads, and have no incentive to make solar look better (or worse) than it actually is.
How we're different
Probability-weighted analysis
We don't just show the best case. Our calculator models pessimistic, realistic, and optimistic scenarios — then gives you the probability-weighted expected value. Real decisions need real uncertainty.
All the costs, not just some
Panel degradation, inverter replacement, battery lifecycle, maintenance costs. Other calculators "forget" these. We include everything that affects your actual return.
No lead gen
Use the calculator without entering your email. We don't sell your details to installers. You won't get calls from salespeople. Promise.
Australian-specific
Real irradiance data for Australian cities. Current federal and state rebates. Time-of-use pricing that reflects how Australian retailers actually charge.
The methodology
We model 25-year cash flows using a 6% discount rate, probability-weighted across three scenarios. Inputs are based on industry data, CER rebate schedules, and published electricity rates.
Who built this
SolarMath was built as an independent project — no VC funding, no solar industry backers, no agenda beyond providing accurate information.
If you're considering solar, you deserve numbers you can trust. That's it.
Get in touch
Found an error? Have a suggestion? Spotted outdated data? I'd genuinely love to hear from you.
Legal stuff
The boring but important bits:
- Privacy Policy — How we handle your data (spoiler: we don't sell it)
- Disclaimer — This calculator provides estimates, not guarantees