Why estimate energy consumption before solar?

Cleaner usage assumptions help avoid oversizing solar around temporary loads or avoidable waste.

How many bills should I review?

Use 12 months when possible. A single bill can miss seasonal heating, cooling, holiday, or travel patterns.

Should future EV charging be included?

Yes, but model it separately so you can compare today's usage against expected future usage.

Interactive solar tool

Energy Consumption Calculator

Estimate monthly, daily, and annual electricity demand from utility bills and major household load categories.

Inputs

Consumption assumptions

Use bill data and major load categories to estimate realistic solar demand.

Methodology

How this calculator works

The Energy Consumption Calculator helps clean up the starting point for solar sizing. It combines bill information and major household loads so you can understand whether your solar estimate is based on current use, future use, or avoidable waste.

What the calculator estimates

Estimated monthly kWh from bill amount and electricity rate.

How appliance, heating, cooling, lighting, and other loads contribute to usage.

A cleaner baseline for panel estimates, battery sizing, and ROI comparisons.

Inputs to verify before using the result

Use 12 months of bill history when possible so seasonal usage is not missed.

Separate future EV charging, heat pumps, or pool equipment from current usage.

Consider easy efficiency fixes before sizing solar around avoidable waste.

For a practical walkthrough, read Home Energy Audit Before Solar and then carry the same usage assumptions into the solar calculators.

Formula used

Bill-derived kWh = monthly electric bill / electricity rate.
Modeled kWh combines major appliances, cooling or heating, lighting, occupants, and miscellaneous load assumptions.
The planning baseline uses the higher estimate so incomplete appliance inputs do not understate real usage.

Key inputs defined

Monthly bill: Your average electric bill before solar. Use several months if your home has strong seasonal cooling or heating swings.
Electricity rate: The price you pay per kilowatt-hour. This converts bill cost into estimated energy use.
Occupants: A household-size input used to sense-check whether the estimate is unusually low or high.
Load categories: Major usage buckets such as appliances, cooling, heating, lighting, electric vehicles, and always-on devices.

Turn usage into system size

Now that you have a monthly usage baseline, estimate how many panels it may take to offset that energy.

Estimate panel count

Build a cleaner usage baseline first

Review the planning hub before sizing solar so usage cleanup and seasonal demand do not distort your proposal comparison.

Read solar planning guide