Power Systems Standard Battery Capacity Formulas Precision Estimator

Wh to mAh Calculator

Convert Watt-hours (Wh) to Milliamp-hours (mAh) and mAh to Wh quickly and accurately. Calculate battery capacity, power bank limits, and lithium battery ratings for 3.7V, 7.4V, 11.1V, and 12V electronics.

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How to Use the Wh to mAh Calculator

Converting Watt-hours (Wh) to Milliamp-hours (mAh) is essential when assessing portable power banks, smartphone batteries, or lithium laptop packs. Follow these simple steps:

  1. 1
    Enter Energy (Wh): Input total energy in Watt-hours into the input field.
  2. 2
    Enter Battery Voltage (V): Input the nominal battery voltage (e.g. 3.7V for single-cell lithium).
  3. 3
    Click Calculate to mAh: Click the button to calculate capacity in Milliamp-hours.
  4. 4
    Review Capacity Output: View battery rating displayed in mAh.

How to Convert Wh to mAh (Sizing Guide)

Watt-hours (Wh) measure total stored electrical energy, whereas Milliampere-hours (mAh) measure electric charge capacity at a specific operating voltage. Multiplying Wh by 1,000 and dividing by battery voltage yields charge capacity: mAh = (Wh × 1000) ÷ V.

Real-Life Wh to mAh Sizing Scenarios

Scenario 1: Smartphone Power Bank Capacity Sizing
A 100 Wh power bank uses internal 3.7V lithium-ion cells:
mAh = (100 Wh × 1000) ÷ 3.7 V = 27,027 mAh

Scenario 2: Laptop Battery Backup Sizing
A high-performance laptop battery is rated for 50 Wh at 11.1V nominal:
mAh = (50 Wh × 1000) ÷ 11.1 V = 4,505 mAh

Step-by-Step Sizing Guide & Formulas

Wh to mAh Formula:
mAh = (Wh × 1000) ÷ V

Step 1: Identify energy (Wh = 10 Wh) and nominal cell voltage (V = 3.7V).

Step 2: Multiply energy by 1,000: 10 × 1000 = 10,000.

Step 3: Divide by voltage: 10,000 ÷ 3.7 = 2,702.7 mAh.

Final Answer: 10 Wh equals approximately 2,703 mAh at 3.7 Volts.

Wh to mAh Sizing Reference Table

The lookup table below details converted Milliampere-hours (mAh) across standard Watt-hour (Wh) battery ratings for 3.7V, 7.4V, 11.1V, and 12V systems:

Energy (Wh) Capacity at 3.7V Capacity at 7.4V Capacity at 11.1V Capacity at 12V
1 Wh270 mAh135 mAh90 mAh83 mAh
10 Wh2,703 mAh1,351 mAh901 mAh833 mAh
28.93 Wh7,514 mAh (3.85V)3,909 mAh2,606 mAh2,411 mAh
50 Wh13,514 mAh6,757 mAh4,505 mAh4,167 mAh
100 Wh27,027 mAh13,514 mAh9,009 mAh8,333 mAh
160 Wh43,243 mAh21,622 mAh14,414 mAh13,333 mAh
240 Wh64,865 mAh32,432 mAh21,622 mAh20,000 mAh
1,000 Wh270,270 mAh135,135 mAh90,090 mAh83,333 mAh

100 wh to mah

100 Watt-hours (Wh) is the maximum battery size allowed in carry-on baggage on commercial flights without airline approval:

  • At 3.7V Cell: (100 Wh × 1000) ÷ 3.7 V = 27,027 mAh
  • At 3.85V Cell: (100 Wh × 1000) ÷ 3.85 V = 25,974 mAh
  • At 12V Battery: (100 Wh × 1000) ÷ 12 V = 8,333 mAh

160 wh to mah

160 Watt-hours (Wh) is the absolute limit for carry-on flight batteries under FAA regulations with prior airline approval:

  • At 3.7V Cell: (160 Wh × 1000) ÷ 3.7 V = 43,243 mAh
  • At 14.8V Drone Battery: (160 Wh × 1000) ÷ 14.8 V = 10,811 mAh

1 wh to mah

1 Watt-hour (Wh) represents energy in small wearable electronics and smartwatches:

  • At 3.7V Cell: (1 Wh × 1000) ÷ 3.7 V = 270 mAh
  • At 5V System: (1 Wh × 1000) ÷ 5 V = 200 mAh

28.93 wh to mah

28.93 Watt-hours (Wh) corresponds to high-end tablet and flagship smartphone battery capacities:

  • At 3.85V Nominal Voltage: (28.93 Wh × 1000) ÷ 3.85 V = 7,514 mAh

1000 wh to mah

1,000 Watt-hours (1 kWh) represents standard capacity for solar power generators:

  • At 12V DC: (1000 Wh × 1000) ÷ 12 V = 83,333 mAh (83.33 Ah)
  • At 24V DC: (1000 Wh × 1000) ÷ 24 V = 41,667 mAh (41.67 Ah)

240 wh to mah

240 Watt-hours (Wh) corresponds to compact portable power stations:

  • At 12V System: (240 Wh × 1000) ÷ 12 V = 20,000 mAh (20 Ah)
  • At 3.7V Cells: (240 Wh × 1000) ÷ 3.7 V = 64,865 mAh

10000 wh to mah

10,000 Watt-hours (10 kWh) corresponds to home lithium energy storage systems:

  • At 48V Nominal DC: (10000 Wh × 1000) ÷ 48 V = 208,333 mAh (208.33 Ah)
  • At 51.2V LiFePO4: (10000 Wh × 1000) ÷ 51.2 V = 195,313 mAh (195.31 Ah)

50000 wh to mah

50,000 Watt-hours (50 kWh) represents energy capacity in commercial battery banks and EV battery packs:

  • At 48V System: (50000 Wh × 1000) ÷ 48 V = 1,041,667 mAh (1,041.67 Ah)
  • At 400V EV Architecture: (50000 Wh × 1000) ÷ 400 V = 125,000 mAh (125 Ah)

12000 wh to mah

12,000 Watt-hours (12 kWh) represents medium off-grid solar storage battery banks:

  • At 48V System: (12000 Wh × 1000) ÷ 48 V = 250,000 mAh (250 Ah)

Frequently Asked Questions (FAQs)

To convert Watt-hours (Wh) to Milliampere-hours (mAh), multiply the energy value in Wh by 1,000 and divide by nominal battery voltage: mAh = (Wh × 1000) ÷ Voltage. For example, a 10 Wh smartphone battery operating at 3.7V nominal yields (10 × 1000) ÷ 3.7 = 2,703 mAh. This conversion depends directly on battery voltage.

The standard conversion formula is mAh = (Wh × 1000) ÷ V, where Wh represents total stored energy in Watt-hours, 1,000 scales Amps to Milliamps, and V represents nominal system voltage in Volts. If battery capacity is measured in Ampere-hours (Ah), the simplified formula is Ah = Wh ÷ V, which is then multiplied by 1,000 to yield mAh.

No, it is physically impossible to convert Watt-hours (Wh) to Milliamp-hours (mAh) without knowing nominal battery voltage. Wh measures actual energy, whereas mAh measures electric charge capacity. Because energy equals charge multiplied by voltage (Wh = mAh × V ÷ 1000), voltage is an indispensable conversion factor. If unspecified, consumer lithium power banks typically use 3.7V cell voltage.

The number of mAh in 1 Wh depends on battery voltage. At a nominal 3.7V lithium cell voltage, 1 Wh equals (1 × 1000) ÷ 3.7 = 270.27 mAh. At a 5V USB output voltage, 1 Wh equals 200 mAh. At 12V DC, 1 Wh equals 83.33 mAh.

Yes, Watt-hours (Wh) is a far more accurate metric for comparing battery energy storage across different devices. mAh only reflects charge capacity at a specific internal cell voltage, which can mislead consumers when comparing power banks operating at different internal voltages (e.g., 3.7V cells vs 11.1V laptop packs). Wh provides a true universal measurement of available work energy.

100 Wh (the standard TSA carry-on flight limit) converts to (100 × 1000) ÷ 3.7 = 27,027 mAh at 3.7V internal lithium cell voltage. If calculated at 3.85V (high-voltage Li-Po smartphone chemistry), 100 Wh equals 25,974 mAh. At 12V battery system voltage, 100 Wh equals 8,333 mAh.

The easiest way is to use our online Wh to mAh calculator. For quick mental calculations on standard 3.7V lithium power banks, multiply the Wh value by 270. For example, a 50 Wh power bank equals 50 × 270 = 13,500 mAh.

Always use the internal cell nominal voltage printed on the battery label. For single-cell lithium-ion power banks, use 3.7V (or 3.85V for smartphone batteries). For 3-cell series laptop batteries, use 11.1V. For 12V automotive or deep-cycle batteries, use 12.0V (or 12.8V for LiFePO4 chemistry).

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