kWh to Ah Calculator
The calculator converts energy measured in kilowatt hours—a common unit used by utilities for billing—to ampere hours, which represent the electrical charge stored in battery systems. The conversion formula used is:
Ah = (kWh ÷ V) × 1000
How to Use the Kilowatt Hours to Amp Calculator
1. Enter Energy in Kilowatt Hours (kWh):
In the first input field, type in the energy value in kilowatt hours. This is the energy used or stored, as seen on your electricity bill or calculated from your system’s requirements. For more insight on reading your power bill and understanding kWh, visit Energy Star’s guide to energy measurements.
2.Enter the Voltage in Volts (V):
In the second field, input the voltage of your battery or electrical system. Voltage is crucial because both kWh and Ah are linked through voltage.
*Learn more about how voltage impacts your system at Calculator.net’s Voltage Calculator.
3.Click "Calculate AMP Hours (Ah)":
Once you’ve entered the kWh and voltage values, click the calculate button. The calculator will perform the conversion based on the formula above.
4.Read the Result
The output will show the equivalent ampere hours (Ah), which indicates the amount of charge delivered by a steady current of one ampere flowing for one hour.
Why Convert kWh to Ah?
Battery Sizing for Solar Systems
One of the most common reasons to convert kWh to Ah is when estimate a solar power system. While solar panels and inverters are often rated in watts or kilowatts, batteries are usually rated in amp hours. To ensure your battery can store enough energy produced by your panels, you need to convert your expected energy usage (in kWh) into Ah based on your system voltage. This ensures your storage is neither too small (causing power shortages) nor unnecessarily oversized (adding to cost).
Related Reading:SEIA’s Solar Industry Resources.
Off-Grid Power Setups
If you're living off the grid, in a cabin, camper, or van, knowing how many Ah you need helps you properly size your battery bank. Say you consume 2 kWh of energy per day and are using a 12V system. Using the formula:
Ah = (kWh × 1000) ÷ V
Ah = (2 × 1000) ÷ 12 = 166.67 Ah
You’ll know that you need at least 167 Ah of battery storage to cover a full day of energy use. This helps you avoid over-discharging your batteries and keeps your power flowing reliably.
Related Reading: NREL’s Off-Grid Solar Resources
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