Ah ↔ mAh

How to use this calculator

One amp‑hour equals one thousand milliamp‑hours: mAh = Ah × 1000 and Ah = mAh / 1000. Type a value in either field and the other updates live, so you can work in whichever unit matches your datasheet or battery label.

What it means in a real circuit

Capacity units appear everywhere in battery work: phone and Li‑ion cells are quoted in mAh (e.g. 3000 mAh), while automotive, solar and industrial packs use Ah (e.g. 100 Ah). Converting between them is constant when sizing a battery for a load, comparing cells, or entering a value into the Battery Life and Charging Time calculators. Keep the unit consistent with the current unit you use elsewhere (mA with mAh, A with Ah).