Table of Contents

To change mAh to Wh, use this formula:

Wh = (mAh × Voltage) / 1000

For example, a 2000 mAh lithium battery at 3.7V gives 7.4 Wh. You need to do this when picking an energy storage system or checking if a forklift battery fits your device’s needs.

mAh to Wh Calculator

mAh to Wh Calculator

Wh: -
Enter capacity and voltage to calculate watt-hours.

mAh to Wh Formula

Key Terms

Before you start any calculation, you need to know what each part of the formula means. Here are the key terms you will see when you convert mAh to Wh:

  • mAh (milliampere-hour): This shows how much electric charge a battery can store. If a battery has more mAh, it can last longer before you need to recharge it.

  • Wh (watt-hour): This tells you how much energy the battery can deliver. You use Wh to compare batteries with different voltages.

  • Voltage (V): This is the force that pushes the electric current. Most batteries have their voltage printed on the label.

Tip: Always check the battery label for these numbers. You will need them for the mAh to Wh calculation.

Why Voltage Matters

You cannot convert mAh to Wh without knowing the voltage. Voltage changes how much energy the battery can give. Two batteries with the same mAh but different voltages will not have the same Wh.

For example, look at this formula:

Wh = (mAh × Voltage) / 1000

If you have a 2000 mAh battery at 3.7V, you get:

Wh = (2000 × 3.7) / 1000 = 7.4 Wh

But if the voltage is 7.4V, the same 2000 mAh battery gives you:

Wh = (2000 × 7.4) / 1000 = 14.8 Wh

You see that voltage makes a big difference. Always use the battery’s nominal or rated voltage. This number is usually printed on the battery or in the product manual. Using the wrong voltage will give you the wrong answer. 

If you cannot find the voltage, do not guess. Look it up in the device manual or ask the manufacturer. Accurate voltage gives you the right mAh to Wh result.

Conversion Steps

Step-by-Step Guide

You can convert mAh to Wh in just a few steps. Follow this guide:

  1. Find the mAh value on your battery label.

  2. Look for the voltage (V) on the same label.

  3. Use the formula: Wh = (mAh × Voltage) / 1000

  4. Multiply the mAh by the voltage.

  5. Divide the result by 1000.

For example, if your battery has 3000 mAh and 3.7V:
3000 × 3.7 = 11,100
11,100 ÷ 1000 = 11.1 Wh

Quick Reference Chart

You can use this chart to quickly check common mAh to Wh conversions. Just match your battery’s mAh and voltage.

mAh

Voltage (V)

Wh

1000

3.7

3.7

2000

3.7

7.4

3000

3.7

11.1

5000

3.7

18.5

10000

3.7

37.0

If your battery uses a different voltage, use the formula for the exact mAh to Wh value.

Practical Uses

Knowing how to convert mAh to Wh helps you in many ways. You can estimate how long your device will run. You can also check if a new battery matches your device’s needs. This skill helps you compare batteries with different voltages. You make better choices when you understand battery energy.

conclusion & FAQ

You now know how to convert mAh to Wh using a simple formula. This skill helps you pick the right battery for your needs. Use the chart and formula whenever you compare batteries. Remember, understanding mAh to Wh gives you more control over your device choices. 

· How do you find the voltage of your battery?

Look at the battery label. You can also check your device’s manual. Most batteries show the voltage in a clear spot.

· Can you convert Wh back to mAh?

Yes, you can! Use this formula:

mAh = (Wh × 1000) ÷ Voltage

Just switch the numbers from the first formula.

· Why do some batteries have different voltages?

  • Different devices use different voltages.

  • The battery’s chemistry changes the voltage.

  • Always use the right voltage for your device to stay safe.

Picture of BSL New Energy Technology Co., Ltd

BSL New Energy Technology Co., Ltd

Founded in 2012, BSLBATT is a leading lithium battery manufacturer and energy storage solution provider in China, specializing in Lithium Iron Phosphate (LiFePO₄) technology. Our products are widely used in home energy storage, electric forklifts, solar systems, golf carts, and RVs. Guided by the mission of “Green Planet, Low-Carbon Guardian,” we are committed to advancing the global shift to renewable energy with safe and efficient lithium battery technology.

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