Wh to mAh Calculator
Convert watt-hours to mAh with voltage input. This is useful for power banks, phone batteries, and portable battery comparisons where energy and charge need to be compared clearly.
Wh to mAh Conversion Tool
Enter watt-hours and voltage to instantly convert battery energy into milliamp-hours. Use the correct nominal chemistry voltage for more realistic results.
Watt-Hours to Milliamp-Hours Converter
This tool uses the standard formula mAh = Wh × 1000 ÷ V and is great for power banks, lithium cells, and phone battery comparisons.
Conversion Results
These results show the converted milliamp-hours, equivalent amp-hours, the entered voltage, and the exact formula used.
Educational Estimates Only: Results depend on the voltage you choose. For batteries and power banks, always verify whether the listed Wh or mAh rating is based on internal cell voltage or output voltage. Verify with datasheets for critical use.
Wh to mAh Basics
Wh is energy and mAh is charge. To convert between them, you need voltage because voltage links stored energy to battery charge.
Watt-hour is a unit of energy, commonly used for batteries and power banks. Milliamp-hour is a unit of charge, so you cannot convert watt-hours into mAh unless you also know the battery voltage.
This is why choosing the correct chemistry voltage matters. Li-ion and LiPo often use 3.7V nominal cell voltage, while LiFePO4 typically uses 3.2V nominal cell voltage. That voltage difference changes the resulting mAh value even when the watt-hour value stays the same.
For example, 37Wh at 3.7V equals about 10000mAh, 100Wh at 3.7V equals about 27027mAh, and 12Wh at 3.2V equals 3750mAh. This makes the tool useful for power banks, phone batteries, and portable electronics where manufacturers may advertise either Wh or mAh.
Conversion formula
- mAh = Wh × 1000 ÷ V.
- Choose correct chemistry voltage.
- Great for power banks.
- Useful for phone batteries.
Examples
- 37Wh @ 3.7V = 10000mAh.
- 100Wh @ 3.7V = 27027mAh.
- 12Wh @ 3.2V = 3750mAh.
What is Wh?
Watt-hour is a unit of energy, commonly used for batteries and power banks. It tells you how much total energy a battery stores.
Can Wh be converted without voltage?
No. Voltage is required to convert Wh to mAh because mAh is charge and Wh is energy. Without voltage, the conversion is incomplete.
Frequently Asked Questions
These are common questions about watt-hours, mAh conversion, voltage choice, and how to compare power banks and battery cells.
What is Wh?
Watt-hour is a unit of energy, commonly used for batteries and power banks.
Can Wh be converted without voltage?
No. Voltage is required to convert Wh to mAh.
What is the formula for Wh to mAh?
mAh = Wh × 1000 ÷ V. Multiply watt-hours by 1000, then divide by battery voltage.
Why does voltage matter?
Because the same watt-hour value produces different mAh results at different voltages.
What is 37Wh at 3.7V in mAh?
37Wh at 3.7V equals 10000mAh.
What is 100Wh at 3.7V in mAh?
100Wh at 3.7V equals about 27027mAh.
What is 12Wh at 3.2V in mAh?
12Wh at 3.2V equals 3750mAh.
Is this useful for power banks?
Yes. Power banks may list either mAh or Wh, and this conversion helps compare ratings more clearly.
Can I use output voltage instead of cell voltage?
You can, but the result will differ. For power banks, check whether the published rating is based on internal cell voltage or USB output voltage.
Is the result exact?
No. It is an educational conversion using nominal voltage. Real-world usable energy varies with system losses and operating conditions.
Compare Battery Ratings Better
Use this calculator to convert watt-hours into mAh, then compare related tools to estimate runtime and compare battery capacity more clearly.
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