Solar Payback Calculator
See how long a rooftop system takes to break even: install cost minus the federal credit, against what the production is worth at your state's rate.
cost/W × size − ITC
production × rate × value
years to break even
3% rate escalation, 0.5%/yr degradation
Results update live as you type. For planning and field-check estimates — always verify against applicable standards and equipment ratings.
How we calculate this →See the levelized cost of energy (LCOE) →What actually drives solar payback
Payback is net cost divided by annual savings, and each side has one dominant lever. On cost, the federal Investment Tax Credit takes 30% off the top for qualifying homeowners, turning a $19,600 install into roughly $13,700. On savings, your utility rate matters more than your sunshine: a system in Massachusetts at 31¢/kWh pays back faster than the same roof in sunnier Arizona at 15¢, because every produced kWh offsets a more expensive one.
The subtle input is the "bill value" of a solar kWh. Under full retail net metering, every kWh you export is worth what you'd have paid — 100%. Under net billing regimes like California's NEM 3.0, exports earn far less than retail, so the blended value of production depends on how much you self-consume. That's what the value slider models, and it's why batteries changed the California calculus — they convert low-value exports into full-value self-consumption.
Realistic modeling also includes 0.5% annual panel degradation and utility rate escalation around 3%; both are built into the 25-year figure above. A payback of 6–10 years against a 25+ year equipment life is the normal shape of a good project.