Solar and Energy Calculators
Estimate solar savings, system size, and household energy costs.
Number of Calculators: 10
What to Know
Sizing a solar installation and estimating what it'll actually save are two different questions, and the calculators here are split accordingly: Solar System Size and Solar Roof Area answer "how big," while Solar Savings and Solar CO2 Savings answer "was it worth it." Electricity Cost and Home Energy Usage are the natural starting point if you don't already know your own baseline usage.
The Solar Savings Journey carries your electric bill straight from Electricity Cost into Solar Savings' own payback-period calculation. Battery Backup and Generator Runtime/Fuel round out the set for anyone planning for an outage rather than a monthly bill.
- Solar Panel SavingsEstimate your solar panel payback period and lifetime savings from your system cost and electric bill.
- Electricity CostEstimate your monthly and yearly electricity cost from your usage in kWh and your rate per kWh.
- Home Energy UsageEstimate how much a single appliance or device costs to run, from its wattage, hours of use, and your electricity rate.
- Voltage DropCalculate how much voltage is lost over a wire run based on its gauge, length, material, and current.
- Solar Panel System SizeEstimate the solar system size (in kW) and number of panels needed to offset your electricity usage.
- Solar Roof AreaFind how many solar panels can physically fit on your roof and the resulting maximum system capacity, from your roof dimensions and panel size.
- Solar CO2 SavingsEstimate the CO2 emissions your solar system avoids each year, using the EPA's own greenhouse gas equivalencies.
- Carbon FootprintEstimate your household's annual CO2 footprint from your electricity, natural gas, and driving usage.
- Battery BackupFind how long a home battery can power your appliances, or how big a battery you need for a target backup runtime.
- Generator Runtime & Fuel ConsumptionFind how long a generator runs on a full tank, and how much fuel a multi-day outage will need.
Guided Journeys
Some of these calculators are also part of a guided journey — a connected chain that carries your numbers forward automatically. A journey may include steps from other categories too.
Solar Savings Journey
Start Journey →Before you can tell whether solar panels are worth it, you need to know what you're actually paying for electricity today, how big a system would even cover that usage, and what payback period that system offers. This journey starts by estimating your current monthly bill from your usage and rate, carries that same usage figure into a system-size estimate (how many kW and panels you'd need), then carries the resulting bill total into the solar payback calculator so you get a real payback period without having to dig up a utility bill or size a system yourself.
- Estimate Your Current Electric Bill
- See What Size System You Need
- See Your Solar Payback Period