About These Calculators
Energy calculators to help you understand your power consumption, plan solar installations, size battery banks, and estimate electricity costs.
Energy Calculators
20 toolsSolar Panel Calculator
Estimate panels, system size, cost, and payback period
Battery Bank Calculator
Size your off-grid battery bank by daily load, voltage, and days of autonomy
Electricity Cost Calculator
Calculate how much your appliances cost to run
kWh Cost Calculator
Calculate electricity cost from kilowatt-hours and rate
Appliance Energy Cost Calculator
Calculate annual energy cost for any appliance
LED Savings Calculator
Calculate savings from switching to LED bulbs
Heat Pump Savings Calculator
Compare heat pump costs vs traditional heating
Insulation R-Value Calculator
Calculate recommended insulation R-value by climate zone
Electricity Bill Calculator
Estimate your monthly electric bill from usage
Power Consumption Calculator
Convert watts to kWh and calculate energy costs
EV Charging Cost Calculator
Calculate the cost to charge your electric vehicle at home
Heat Pump vs Furnace Calculator
Compare heat pump costs to traditional furnace heating
Solar Panel Payback Calculator
Calculate how long until your solar panels pay for themselves
Energy Audit Savings Calculator
Estimate savings from common home energy improvements
Insulation R-Value Needs Calculator
Calculate the R-value insulation you need for your climate zone
Generator Fuel Runtime Calculator
Generator Fuel Runtime Calculator — calculate how long your generator will run on a tank of fuel
Appliance Electricity Cost Calculator
Calculate what it costs to run any appliance
Room AC BTU Calculator
Calculate the right AC size for your room
Solar vs Grid vs Generator Cost Calculator
Compare 20-year costs of solar panels, grid electricity, and generator power including installation, maintenance, fuel, and rate increases
Summer Utility Cost Calculator
Estimate summer cooling costs based on your AC usage, home size, and region
Frequently Asked Questions
Are these energy calculators free?
Yes, all 20 calculators are completely free with no signup required. They run entirely in your browser — no data is sent to any server.
How accurate are these calculators?
Our calculators use industry-standard formulas and are regularly updated. However, they provide estimates — always verify critical calculations with a professional in the relevant field.
Can I use these calculators on my phone?
Yes, all calculators are mobile-responsive and work on any device with a web browser. No app download needed.
Do you save my calculations?
No. All calculations happen in your browser. We don't store any of your inputs or results. Your data stays on your device.
Can I embed these calculators on my website?
Select calculators offer embed codes that you can copy and paste into your website or blog. Look for the "Embed This Calculator" section on individual tool pages.