1,221 mAh Is How Many Wh?

Quick Answer: 1,221 mAh = 4.5177 Wh (at 3.7V)

mAh → Wh Wh → mAh
Milliamp-hours
=
Watt-hours
Auto-fills voltage
Nominal battery voltage
Conversion Result
1,221 mAh = 4.5177 Wh (at 3.7V)

At 3.7V nominal voltage

1,221 mAh = 4.5177 Wh (at 3.7V)

Step-by-step:

  1. Formula: Wh = mAh × V / 1,000
  2. 1,221 × 3.7 / 1,000 = 4.5177 Wh

Similar mAh to Wh Conversions

Values close to 1,221 mAh (at 3.7V Li-ion):

mAh Wh (at 3.7V)
1 mAh 0.0037 Wh
501 mAh 1.8537 Wh
1,001 mAh 3.7037 Wh
1,501 mAh 5.5537 Wh
2,001 mAh 7.4037 Wh
2,501 mAh 9.2537 Wh
3,001 mAh 11.1037 Wh
3,501 mAh 12.9537 Wh

Popular mAh to Wh Conversions

500 mAh1.85 Wh 1,000 mAh3.7 Wh 1,500 mAh5.55 Wh 2,000 mAh7.4 Wh 2,500 mAh9.25 Wh 3,000 mAh11.1 Wh 3,500 mAh12.95 Wh 4,000 mAh14.8 Wh 5,000 mAh18.5 Wh 6,000 mAh22.2 Wh 10,000 mAh37 Wh 15,000 mAh55.5 Wh

See Also

Frequently Asked Questions

How many Wh is 1,221 mAh?

1,221 mAh equals 4.5177 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 1,221 mAh to Wh?

Multiply 1,221 by the battery voltage, then divide by 1,000. At 3.7V: 1,221 × 3.7 / 1,000 = 4.5177 Wh.

Is 1,221 mAh allowed on a plane?

At 3.7V, 1,221 mAh = 4.5177 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
Adilson Fernandes By Adilson Fernandes
Tiago Fernandes Reviewed by Tiago Fernandes