kWh Calculator
Device energy: watts × time ÷ 1,000. Click any i for detail.
Device
Watts
i
Watts
Average draw while on, not the peak nameplate if they differ. |
|
|---|---|
Hours per day
i
Hours
Hours the device actually runs each day. |
|
Days
i
Days
Billing window or how many days you want to total. |
|
Rate ($/kWh)
i
Rate
Optional. Your all-in kWh price if you want a dollar sketch. |
How to use this calculator
- Enter average watts.
- Enter hours per day and days.
- Optionally add $/kWh.
- A whole-bill kWh line belongs on the electricity cost page.
Results explained
kWh = watts × hours × days ÷ 1,000. Cost = kWh × rate. That is device math, not a meter read.
Quick reference: kWh
A 100 W lamp for 10 hours is 1 kWh.
| Item | Detail |
|---|---|
| 1,000 W for 1 hour | 1 kWh |
| 100 W × 8 h × 30 d | 24 kWh |
| Bill from kWh | Electricity cost calculator |
| 3D printer job | 3D print cost (grams + kWh) |
Standby watts still count if you include them in hours.
How the estimate is built
kWh = W × h × days / 1000. cost = kWh × rate.
Example scenario
100 W × 8 h × 30 days = 24 kWh ≈ $3.84 at $0.16/kWh.
FAQ
I already have kWh from the bill?
Use the electricity cost calculator.
Duty cycle?
Use average watts, or hours × fraction on.
Solar offset?
Not modeled.