Terms of Use

By using WattMath, you agree to these Terms of Use. Please read them before relying on our calculator results.

Estimates, Not Advice

All calculator outputs — including payback periods, cost savings, system sizes, and incentive amounts — are estimates for informational purposes only. They do not constitute financial, tax, investment, or professional advice. Actual results depend on many factors specific to your home, utility, installer, and financial situation that these calculators cannot fully account for.

Before making any major energy investment (solar installation, EV purchase, heat pump replacement, etc.), consult with qualified professionals including a licensed contractor, tax advisor, and/or financial advisor.

No Tax Credit Determinations

WattMath displays current federal tax credit rates and may indicate that you "may qualify" for certain credits. We do not determine your eligibility for any federal, state, or local tax credit or incentive. Tax credit eligibility depends on income, filing status, tax liability, and other factors that only a qualified tax professional can assess. Always refer to IRS publications and consult a tax advisor.

Data Accuracy

We strive to use accurate, up-to-date data from authoritative sources including NREL, EIA, and IRS publications. However, incentive programs change, utility rates fluctuate, and equipment costs vary. We make no warranty that our data is current or accurate for your specific location and situation.

Affiliate Relationships

WattMath may earn commissions from affiliate links to products and services. These relationships do not influence our calculator methodology or results. We disclose affiliate relationships where they appear.

Intellectual Property

Calculator methodology, source code, and content on WattMath are proprietary. You may share links to our calculators freely. Reproducing our calculator logic or content without permission is not permitted.

Limitation of Liability

WattMath is provided "as is" without warranties of any kind. To the maximum extent permitted by law, we are not liable for any damages arising from your use of or reliance on our calculators.

Changes to These Terms

We may update these Terms at any time. Continued use of WattMath after changes constitutes acceptance of the updated Terms.

Contact

Questions? Email us at legal@wattmath.com.