4,200 mAh Is How Many Wh?

Q: How many Wh is 4,200 mAh?

4,200 mAh = 15.54 Wh at 3.7V (Li-ion nominal voltage). The exact Wh depends on the battery voltage: Wh = mAh x V / 1,000.

Quick Answer: 4,200 mAh = 15.54 Wh (at 3.7V)

mAh → Wh Wh → mAh

mAh Milliamp-hours

Wh Watt-hours

Battery type Auto-fills voltage

Voltage (V) Nominal battery voltage

Conversion Result

4,200 mAh = 15.54 Wh (at 3.7V)

At 3.7V nominal voltage

4,200 mAh = 15.54 Wh (at 3.7V)

Step-by-step:

Formula: Wh = mAh × V / 1,000
4,200 × 3.7 / 1,000 = 15.54 Wh

Similar mAh to Wh Conversions

Values close to 4,200 mAh (at 3.7V Li-ion):

mAh	Wh (at 3.7V)
1,700 mAh	6.29 Wh
2,200 mAh	8.14 Wh
2,700 mAh	9.99 Wh
3,200 mAh	11.84 Wh
3,700 mAh	13.69 Wh
4,200 mAh	15.54 Wh
4,700 mAh	17.39 Wh
5,200 mAh	19.24 Wh
5,700 mAh	21.09 Wh
6,200 mAh	22.94 Wh
6,700 mAh	24.79 Wh

Popular mAh to Wh Conversions

Frequently Asked Questions

How many Wh is 4,200 mAh?

4,200 mAh equals 15.54 Wh at 3.7V (Li-ion nominal voltage). The exact Wh depends on the battery voltage: Wh = mAh × V / 1,000.

How do I convert 4,200 mAh to Wh?

Multiply 4,200 by the battery voltage, then divide by 1,000. At 3.7V: 4,200 × 3.7 / 1,000 = 15.54 Wh.

Is 4,200 mAh allowed on a plane?

At 3.7V, 4,200 mAh = 15.54 Wh. Airlines allow lithium batteries up to 100 Wh in carry-on luggage. Batteries between 100–160 Wh require airline approval. Batteries over 160 Wh are prohibited on passenger aircraft.

More mAh to Wh conversions

Formula: Wh = mAh × V / 1,000. Results assume nominal battery voltage.

Conversion factors verified against NIST, BIPM Based on SI definitions (BIPM). Last reviewed: March 2026