Ah to Amps Calculator
Convert amp-hours (Ah) to amps (A) with time—A = Ah ÷ hours. Bidirectional (also A → Ah). Not Ah↔Wh energy conversion.
Calculator
Quick: Ah + hours → A. Advanced: A → Ah, mAh/mA, minutes or days.
About this calculator
This amp hours to amps calculator converts capacity and time into average current with A = Ah ÷ h. It does not convert Ah to Wh (needs voltage)—use Ah to Wh. For pack hours at a known load use battery runtime. Browse the power calculator hub.
Calculation Results
≈ 5 A (5000 mA)
100 Ah ÷ 20 h
Formula: A = Ah ÷ hours
Time assumption: default 20 h (C20). Ideal average current only—Peukert and voltage sag at high C-rate are not modeled.
Ah to amps quick reference
A = Ah ÷ hours. Default planning window is often C20 (20 h). Click a row to load the calculator.
| Ah | Time | Amps |
|---|---|---|
| 1 h | 1 A | |
| 20 h (C20) | 5 A | |
| 5 h (C5) | 20 A | |
| 1 h | 100 A (1C) | |
| 4 h | 40 Ah |
Amp hours to amps formula
A = Ah ÷ hours
Reverse: Ah = A × hours. Convert minutes ÷ 60 and days × 24 before dividing.
Time assumption: Many datasheets quote capacity at a 20-hour (C20) rate. This page defaults to 20 h so 100 Ah → 5 A, matching A1Solar/JMH-style Ah÷hours tables—not “100 Ah = 100 A”.
- Ah — amp-hour capacity (mAh ÷ 1000).
- hours — discharge or charge duration.
- A — average current in amperes.
Example: 100 Ah ÷ 20 h = 5 A. So 100 Ah is not 100 A unless the time is 1 hour.
Energy (Wh): Ah to Wh calculator. Hours at a load: battery runtime.
When to use which battery tool
| Goal | Tool |
|---|---|
| Ah + time → average amps | This page — Ah to Amps |
| Ah ↔ Wh (needs voltage) | Ah to Wh calculator |
| Ah + load → hours | Battery runtime calculator |
| UPS Ah for backup minutes | UPS battery sizing |
Frequently Asked Questions
How many amps are in 1 amp-hour?
1 Ah ÷ 1 h = 1 A. Over 20 h (C20), 1 Ah ≈ 0.05 A. Amp-hours always need a time window—they are not amps by themselves.
How do you convert Ah to amps?
A = Ah ÷ hours. Example: 100 Ah over 20 h ≈ 5 A. Convert minutes or days to hours first. Use the C20 / C5 / 1C chips above for common windows.
What is 100Ah in amps?
100 Ah is not 100 A. You need time: at 20 h ≈ 5 A; at 5 h ≈ 20 A; at 1 h ≈ 100 A (idealized 1C).
How do I convert amps to amp hours?
Ah = A × hours. Example: 10 A for 4 h ≈ 40 Ah before DoD and Peukert.
Is Ah to amps the same as Ah to Wh?
No. This page needs time. Energy conversion needs voltage—use the Ah to Wh calculator.
How is this different from a battery runtime calculator?
This page turns Ah + time into average amps (or reverse). The battery runtime calculator estimates hours from capacity and load.