Amp Hours (Ah) to Amps (A) Calculator

Use this free tool to calculate the current draw in amps based on battery capacity and runtime. Ideal for off-grid systems, solar setups, and load sizing.

Formula

Amps (A) = Amp Hours (Ah) ÷ Time (hours)

Amp Hours (Ah) = Amps (A) × Time (hours)

Example Calculations

• 100 Ah over 10 hours = 10 A
• 60 Ah over 6 hours = 10 A
• 120 Ah over 4 hours = 30 A
• 20 A for 5 hours = 100 Ah
• 15 A for 3 hours = 45 Ah

Frequently Asked Questions (FAQs)

1. Why do I need to input time?

Amp-hours indicate total energy. To calculate amps, you must know how quickly that energy is used—which is where time comes in.

2. What if I want to find amp hours instead?

Scroll down to use the reverse calculator on this page: just multiply amps by time to get Ah.

3. What happens if I enter zero or a negative value?

The calculator ignores invalid entries like zero or negative numbers. Please enter positive values only.

4. Can I use decimal values?

Yes, the calculator supports decimal inputs for both amp-hours and time. It rounds output to two decimal places for clarity.

Where This Is Used

• Off-grid battery banks: To determine how much current a battery will deliver over time
• Solar power systems: To size solar charge controllers and inverters
• Load calculations: To estimate current draw for lighting, appliances, and tools
• Marine & RV power planning: For calculating how long a load can be supported by a battery

More Tools & Resources

Looking for more ways to plan your off-grid system? Check out our additional calculators and resources:

→ More Calculators