Device Power Calculator
Choose from common device presets or enter custom wattage. See daily, monthly and yearly electricity costs per device. Compare multiple devices. Runs locally.
100% Private & Secure
This tool runs in your browser.
Your data is never uploaded or stored.
Electricity Rate
Add 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 30 days
Yearly cost = Daily cost x 365 days
Standby cost = Standby W / 1000 x Standby hours x 365 x Rate
How to use
- 1
Select a device preset or enter custom wattage.
- 2
Set daily usage hours.
- 3
See cost estimates and add more devices.
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.