Decision workspace
One plan that keeps your numbers
Save scenarios, compare outcomes, share an address-safe link, and print a homeowner-ready report.
Open my solar planKnow your solar numbers before you call an installer
Free, accurate solar calculators and an up-to-date incentive database for US homeowners. Real production estimates from NREL PVWatts® — no email required.
Updated for 2026: the 30% federal solar tax credit for homeowners ended on Dec 31, 2025. Unlike most calculators, Wattcrunch uses the current rules — so your numbers are honest. See what changed →
Start Here
Build your solar plan in one guided flow
Enter your household basics once. We’ll carry them through system sizing, solar production, savings, financing, and incentives so you don’t keep retyping the same assumptions.
kWh/yr
$/kWh
$/W
Use real bill history
Import a text-based PDF, CSV, or text export with monthly kWh. Files are processed in memory and are not retained.
What the workflow answers
- How big your system should be
- How much your roof can produce
- What solar is likely to save you
- Whether cash, loan, or lease looks better
- Which incentives still matter in 2026
Proposal intelligence
Compare up to three installer quotes
Normalize total payments, price per watt, production, equipment, batteries, and warranty coverage.
Compare solar quotesPrimary-source research
Check the utility rule behind savings
Review billing models, tariff questions, source dates, and official utility verification links.
Browse utility guidesSystem Size Calculator
Turn your annual kWh usage into the right solar system size in kW.
Open tool →Solar Savings Calculator
25-year savings, payback, ROI, and NPV with up-to-date 2026 tax rules.
Open tool →Incentive Finder
Search federal, state, and utility solar incentives by state.
Open tool →Solar planning in plain English
The four numbers to check before comparing solar quotes
A useful solar estimate connects your electricity use, local sunlight, installed price, and utility export policy. Wattcrunch keeps those assumptions visible so you can change them instead of trusting a hidden sales estimate.
01
Annual electricity use
Use 12 months of bills in kWh. Square footage alone cannot size a solar system accurately.
Calculate system size02
Local solar production
A 1 kW array produces different amounts by location, roof direction, tilt, and losses. We use NREL PVWatts for address-based estimates.
Check solar potential03
Installed price per watt
Compare quotes before financing. Equipment, roof work, batteries, and dealer fees should be separated clearly.
Check a solar quote04
Import and export rates
Retail electricity avoided on-site can be worth more than exported solar. Net metering and time-of-use rules materially change savings.
Model net meteringWant to audit the assumptions? Read our calculator methodology and editorial policy.
🌳See your solar carbon impact →
Wattcrunch is free. Help us give back.
Every calculation here is free with no account or email required. Advertising supports the site but never changes your inputs, results, or recommendations. If these tools helped you make a smarter solar decision, consider planting a tree through One Tree Planted. One dollar plants one tree, and it takes about 30 seconds.
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