"How much will solar actually save me?" is usually the first question anyone asks before going solar — and it's a different question from "how long until it pays for itself." This calculator answers the savings question directly: the money that stays in your pocket each month, each year, and across the system's 25-year life. If you want the payback period and return on investment instead, our solar ROI calculator handles that side.
How solar savings actually work
Every kilowatt-hour (kWh) your panels produce is a kilowatt-hour you don't buy from the grid. So your saving isn't really about the panels — it's about the grid electricity you avoid paying for. That makes the calculation simple at its core:
Monthly saving = kWh offset by solar × your electricity rate
If your system covers 400 kWh a month and you pay 0.12 per unit, that's about 48 a month, or 576 in the first year. Straightforward — but the first year is only the beginning of the story.
Why savings grow every single year
Electricity prices almost never stay flat. They creep up most years, and that steady climb is what makes solar savings grow over time. Your system keeps producing roughly the same energy, but each unit it produces is worth more as grid prices rise. A system saving 576 in year one might save well over 1,000 a year two decades later — for the same energy. That's why the 25-year total is far larger than simply multiplying the first year by 25, and why the chart above curves upward. This calculator lets you set an annual price increase (a few percent is typical) so the lifetime figure reflects reality rather than a flat guess.
What share of your bill does solar cover?
Savings only tell half the story — the other half is how much of your bill disappears. If you enter your current monthly bill, this calculator shows what percentage of it your solar offset covers. A well-sized system can wipe out most of a bill, though you'll often still pay fixed grid connection or standing charges that solar can't touch. Seeing the coverage percentage helps set realistic expectations: "solar covers about 70% of my bill" is a more honest picture than "solar eliminates my bill."
Getting your numbers right
The two inputs that matter most are the monthly kWh your system offsets and your electricity rate. If you don't know how much energy your system will produce, estimate it first with our energy production calculator, which turns system size and local sun hours into monthly kWh. For your rate, check a recent bill — divide the total by the kWh used to get your real effective rate, which is often higher than the headline tariff once fees are included.
Savings vs payback — use both tools
This calculator and the ROI calculator are two sides of the same decision. Bill savings answers "how much will I save?"; ROI answers "how long until the system pays for itself, and what's my total return?" Together they give you the full financial picture. Most people find it clearest to look at the savings first — the number is motivating and easy to grasp — then check the payback period to confirm the investment makes sense.
Frequently asked questions
How much will solar save me on my electricity bill?
Your monthly saving is the grid electricity your system replaces, valued at your rate. Offset 400 kWh a month at 0.12 per kWh and that's about 48 per month, or 576 the first year. The 25-year total is much larger because prices keep rising, which this calculator factors in.
Why do my solar savings grow every year?
Because electricity prices rise over time. Every unit your system produces is a unit you don't buy, so as grid prices climb, the value of your self-produced energy climbs too. A system saving 600 in year one can save more than double that per year two decades later.
What is the difference between bill savings and payback period?
Bill savings is the money the system keeps in your pocket over time. Payback period is how long those savings take to equal what you paid. This tool focuses on the savings; use the ROI calculator for payback and long-term return.
What percentage of my electricity bill can solar cover?
It depends on system size versus your usage. A system producing as much as you use over a year can offset most or all of your bill, though fixed grid fees may remain. Enter your current bill above to see the share your solar offset covers.