Independent solar planning
About Watt My Roof
Watt My Roof was created to make a complicated first question easier: how many solar panels might a particular home actually need?
Give homeowners a fast, understandable starting estimate without requiring a phone number, sales consultation or installation quote.
Why this calculator is different
Many quick estimates start and stop with square footage. Watt My Roof lets you begin with home size, then account for appliances and high-energy loads such as an electric dryer, central HVAC, water heating, an electric vehicle or a pool pump. If you know your actual monthly kWh, that bill-based number can replace the home estimate.
What we are—and what we are not
Watt My Roof is an independent educational website and planning tool. It is not a solar installer, equipment manufacturer, utility, engineering firm, financial adviser or permitting authority. The result is meant to help you understand the scale of a possible system and ask better questions.
A final solar design must be based on your complete electricity history, roof dimensions and condition, shade, local weather, equipment specifications, utility rules, permitting requirements and a professional site assessment.
Transparency before monetization
The calculator result is based on the inputs and formula described in our methodology. It is not adjusted to favor a company or product. If Watt My Roof earns money from an affiliate link, sponsorship or other commercial relationship, that relationship will be disclosed clearly. Read the full affiliate disclosure.
Who writes and reviews this
Content on Watt My Roof is produced by the Watt My Roof Research Team. Every assumption in the calculator and guides—home-size baselines, appliance load estimates, panel output and the 20% system-loss allowance—is checked against publicly available data from sources such as the U.S. Department of Energy, the U.S. Energy Information Administration and panel manufacturer specifications, and is revised when those sources change. Pages show the date they were last reviewed. We do not employ individual licensed engineers or electricians, and nothing on this site is a substitute for a site-specific assessment from a qualified, licensed professional.
Our editorial standard
- State the important assumptions instead of hiding them.
- Separate educational estimates from professional installation advice.
- Correct material errors when they are identified.
- Label affiliate or sponsored relationships where readers encounter them.
- Prefer useful, specific explanations over inflated savings promises.