Want to know how long your device’s battery will last? Use this simple calculator to estimate battery life based on capacity, power usage, and efficiency. Whether it’s for a phone, laptop, or gadget, this tool helps you figure out how much time you can expect before the next charge.
Battery Life Calculator
Calculate how long your device will last on a single charge
Estimated Battery Life
Daily Usage
0 days
Energy
0 Wh
Based on battery capacity and device power consumption
How to Calculate Battery Life
Battery life depends on a few key factors:
- Battery Capacity (mAh or Wh): The total amount of energy the battery can store.
- Device Power Consumption (W or mA): How much energy your device uses while running.
- Efficiency: Not all energy is used perfectly—heat and other losses reduce actual usage time.
The general formula is:
Battery Life = Battery Capacity ÷ Device Power Consumption
For example, if you have a 4000 mAh smartphone battery and your phone uses 400 mA per hour, you’ll get about 10 hours of use before needing a recharge.
Why Battery Life Matters
Knowing battery life helps you:
- Plan usage for travel or work.
- Compare devices more accurately.
- Avoid running out of power at the worst time.
Whether you’re checking your phone, laptop, or any rechargeable device, our calculator gives you a quick and reliable estimate.
