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Electricity Cost Calculator
Enter device wattage, daily usage hours and electricity rate to see daily, monthly and yearly costs. Add multiple devices for a total estimate. Runs locally.
100% Private & Secure
This tool runs in your browser.
Your data is never uploaded or stored.
Electricity Rate
$per kWh
Quick Add Preset Devices
Add Custom Device
No devices added yet. Use the quick presets above or add a custom device.
Formula Reference
Daily energy (kWh) = Watts (W) x Hours per day / 1000
Daily cost = Daily energy (kWh) x Rate ($/kWh)
Monthly cost = Daily cost x Days per month
Yearly cost = Monthly cost x 12
How to use
- 1
Enter device wattage and daily usage.
- 2
Enter your electricity rate.
- 3
See daily, monthly and yearly costs.
Why use this tool?
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Fast, instant results — no waiting, no page reloads.
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Clean, focused interface designed for developers.
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100% private — everything runs in your browser, nothing is uploaded to any server.
Frequently Asked Questions
What is the default electricity rate?
It defaults to $0.12/kWh. Adjust to match your local rate.
Can I add multiple devices?
Yes. Add as many devices as you need for a total cost estimate.