About WattSpend
WattSpend answers one question for American homeowners and car shoppers: what will this actually cost me? Charging an EV, switching to a heat pump, installing a charger, adding a battery, each tool turns your rates and your gear into a dollar figure you can plan around.
Where the numbers come from
| Electricity rates. EIA state residential averages | refreshed monthly |
| EV efficiency & batteries. EPA ratings, manufacturer specs | refreshed quarterly |
| Fuel prices. AAA and EIA national averages | refreshed monthly |
| Heating & equipment. DOE reference values, contractor quote ranges | reviewed yearly |
How we work
Every calculator prints its formula on the page. If you disagree with an assumption, you can see exactly where it bites.
Averages get you started; your utility bill wins. Autofilled values are marked and always overridable.
Rates vary by utility and season. We label example values and date every page.
WattSpend is reader-supported: ads and affiliate links (marked) keep the tools free. We are not affiliated with any utility or automaker, and nothing here is financial or electrical advice, get real quotes for real projects.