This Battery Life Calculator helps you estimate how long your device can run based on its battery capacity, voltage, and power consumption. Whether you're analyzing smartphone usage, testing power banks, comparing rechargeable batteries, or planning outdoor electronics, this tool gives you a clear, real-time calculation of expected runtime.
Designed for hobbyists, technicians, and everyday users, the calculator converts mAh to Wh automatically and delivers accurate results in just one click. It’s fast, lightweight, and works directly in your browser—no installation required.
With this tool, you can easily:
- Estimate battery life for phones, laptops, cameras, flashlights, drones, RC devices, and more
- Compare different battery capacities and voltages
- Calculate real energy consumption in Wh
- Optimize your battery usage for travel or professional work
Use the calculator below to get an instant, precise runtime estimate.
nks, comparing rechargeable batteries, or planning outdoor electronics, this tool gives you a clear, real-time calculation of expected runtime.
Designed for hobbyists, technicians, and everyday users, the calculator converts mAh to Wh automatically and delivers accurate results in just one click. It’s fast, lightweight, and works directly in your browser—no installation required.
With this tool, you can easily:
- Estimate battery life for phones, laptops, cameras, flashlights, drones, RC devices, and more
- Compare different battery capacities and voltages
- Calculate real energy consumption in Wh
- Optimize your battery usage for travel or professional work
FAQ
1. How accurate is this battery life calculator?
The calculation is based on theoretical values (Wh ÷ device power in watts). Real-world results may vary due to system inefficiency, temperature, aging, and usage conditions.
2. What information do I need to use this tool?
You only need:
- Battery capacity (mAh)
- Battery voltage (V)
- Device power consumption (W)
3. How do I find my device’s power consumption?
You can check the device manual, power adapter label, or power specifications on the manufacturer’s website. For USB-powered devices, a USB tester can measure it directly.
4. Does higher mAh always mean longer battery life?
Not always. Voltage, device efficiency, and power draw all influence total runtime. A higher mAh battery with lower voltage may deliver less actual energy.
5. Can I use this calculator for power banks?
Yes. Simply enter the power bank's capacity (mAh), voltage (usually 3.7V), and the wattage of the device you're charging.
6. Can I use this calculator for laptops or large devices?
Yes—just convert your battery’s Wh value to mAh if necessary or enter values directly. It works for everything from smartphones to solar generators.
7. What’s the formula behind the calculation?
The calculator uses:
Battery Life (Hours) = (mAh × V / 1000) ÷ W
Use the calculator below to get an instant, precise runtime estimate.