🔋 Battery Life Estimator

Estimate how long your device’s battery will last based on its capacity and your device’s power consumption.

Battery Calculator


Estimated Battery Life: -
This is a theoretical estimate. Real-world battery life depends on temperature, background apps, and efficiency.

How to Estimate Battery Life Effectively

Battery life is one of the most important aspects of modern devices — from smartphones and laptops to tablets and wearables. Understanding how long your battery will last helps you plan your usage, avoid running out of charge at critical times, and even extend your device’s lifespan.

1. The formula behind battery life

The basic calculation for battery life is:

Battery Life (hours) = Battery Capacity (mAh) ÷ Device Consumption (mA)

This gives a theoretical value assuming constant consumption. For example, a 4000 mAh battery powering a device that draws 500 mA will last about 8 hours (4000 ÷ 500).

2. Why real-world results differ

  • Usage patterns: Gaming and video streaming drain batteries faster than browsing or standby.
  • Temperature: Extreme heat or cold reduces efficiency.
  • Battery health: Over time, batteries lose capacity due to charge cycles.

3. How daily usage impacts battery life

If you only use your device for 4 hours daily, a device with 8 hours of continuous runtime could last 2 days before needing a recharge. That’s why this calculator includes a daily usage option — giving you a practical perspective on battery life.

4. Tips to extend your battery

  • Lower screen brightness and use dark mode where possible.
  • Turn off Bluetooth, GPS, or Wi-Fi when not needed.
  • Close background apps that constantly consume power.
  • Keep your device in moderate temperature ranges.

5. Conclusion

Estimating battery life helps you manage power more effectively. With this Battery Life Estimator, you can better understand how your device performs and make informed choices to maximize time between charges.