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Watt-Hours to mAh

Convert watt-hours to milliamp-hours using a voltage you type. Wh = (mAh / 1000) × V. Milliamp-hours are charge, not energy, until you multiply by volts. The energy hub does not list mAh.

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How to convert watt-hours to milliamp-hours

  1. Enter watt-hours. The default is 10 Wh.
  2. Enter the pack voltage in volts. The default is 3.7 V, a common lithium-ion cell nominal. Voltage must be greater than 0.
  3. Keep From as Watt-hours and To as Milliamp-hours, or pick Amp-hours.
  4. Read mAh. Divide Wh by V, then multiply by 1000. Swap units to start from mAh.

Watt-hour

Energy plus a voltage to reach charge

Watt-hourEnergy, 1 Wh = 3600 J
Milliamp-hourCharge, 1 mAh = 3.6 C
VoltageRequired. Wh = (mAh / 1000) × V
Amp-hour1 Ah = 1000 mAh
Energy hubJoules and kWh without mAh, because charge needs V
Nominal cell3.7 V is a label, not a live battery reading

What watt-hours to mAh does

Phone and pack labels mix watt-hours (energy) and milliamp-hours (charge). They are not the same dimension until you name a voltage. This page requires volts. It uses Wh = (mAh / 1000) × V. Ten watt-hours at 3.7 V is about 2702.7 mAh. The energy converter converts joules, calories, watt-hours, and kWh without asking for voltage, so it cannot list mAh.

Current from power is watts to amps. That job is a rate at one instant, not a stored mAh figure.

Watt-hour and milliamp-hour formula

mAh = (Wh / V) × 1000. Wh = (mAh / 1000) × V. Ah = Wh / V. If voltage is missing or not greater than 0, the engine shows an error. Nominal 3.7 V is a convention for many lithium-ion cells. A 2S pack needs about 7.4 V in this field if you use that nominal. Real voltage sags with load and state of charge.

Charge, energy, and pack labels

Airlines quote watt-hours for spare lithium batteries. A 20 Wh limit is energy. A 5000 mAh power bank still needs V to become Wh. USB power banks often use 3.7 V cell mAh while the 5 V output energy is less after conversion loss. This page does not apply converter efficiency.

When to convert watt-hours to mAh here

Turn a Wh airline figure into mAh at a named voltage, or turn a cell mAh into Wh for a label. Leave kWh utility bills on the energy converter. Leave watts and amps on watts to amps.

What this page does not do

It does not guess voltage. It does not apply DC-DC efficiency. It does not convert joules unless you first turn them into watt-hours on the energy page. Input stays in this tab.

Watt-hours to mAh questions

Why do I have to enter voltage?
mAh is charge. Wh is energy. Energy = charge × voltage.
What is the formula?
Wh = (mAh / 1000) × V, and mAh = (Wh / V) × 1000.
Why is 3.7 V the default?
It is a common lithium-ion nominal cell voltage, not a measurement of your pack.
Is this on the energy converter?
No. That hub has no mAh because it never asks for volts.
How do I convert 5000 mAh at 3.7 V to Wh?
Swap to From Milliamp-hours, keep 3.7 V: 5 × 3.7 = 18.5 Wh.
Does this include charger loss?
No. Type the energy or charge you already have.