kwh to mah calculator

How to convert kWh to mAh

Converting kWh to mAh is common when you want to compare large energy storage (like home batteries or solar systems) with smaller battery specs used in electronics. The key thing to remember is that mAh depends on voltage. You cannot convert kWh to mAh accurately without specifying volts.

Core conversion formula

Use this equation:

mAh = (kWh × 1,000,000 × efficiency) ÷ voltage

• kWh = energy in kilowatt-hours
• 1,000,000 = conversion factor from kWh to mWh
• efficiency = decimal value (100% = 1.0, 90% = 0.9)
• voltage = battery/system voltage in volts

If you don’t want to model losses, keep efficiency at 100%.

Why voltage matters so much

Two batteries can have the same kWh rating but different mAh values because they run at different voltages. For a fixed amount of energy, lower voltage means higher current capacity (mAh), and higher voltage means lower mAh.

That’s why phone batteries (around 3.7V) show large mAh numbers, while higher-voltage battery systems may show smaller mAh despite holding more total energy.

Quick examples

Example 1: 1 kWh at 12V

mAh = (1 × 1,000,000) ÷ 12 = 83,333.33 mAh

Example 2: 2.4 kWh at 48V

mAh = (2.4 × 1,000,000) ÷ 48 = 50,000 mAh

Example 3: 5 kWh at 24V with 92% efficiency

mAh = (5 × 1,000,000 × 0.92) ÷ 24 = 191,666.67 mAh

Common use cases

• Comparing power station energy with device battery ratings
• Estimating battery bank capacity for RV, marine, or off-grid solar setups
• Planning inverter runtime with real-world efficiency losses
• Converting between system-level energy (kWh) and battery-level capacity (mAh/Ah)

Reference voltages (typical)

Battery Type / System	Typical Voltage
Single Li-ion cell	3.6V–3.7V nominal
USB power bank output	5V
Car electrical system	12V
Small solar/battery bank	24V
Home storage / EV subsystem	48V and above

Frequently asked questions

Is mAh better than kWh?

Not better—just different. kWh is better for total energy comparison across systems. mAh is useful for batteries and electronics at known voltage.

Can I convert kWh to mAh without voltage?

No. Voltage is required because mAh is charge capacity, while kWh is energy.

Should I include efficiency?

If you want realistic usable capacity, yes. Real systems lose energy in conversion, heat, and electronics. Typical overall efficiency assumptions range from 85% to 95% depending on hardware.

Bottom line

This kWh to mAh calculator gives you a fast and accurate way to translate energy into battery-style capacity at any voltage. Enter your energy value, select voltage, add efficiency if needed, and you’ll get both mAh and Ah instantly.