Ah to Wh & Wh to Ah Calculator
Easily convert your battery capacity from Ampere-hours (Ah) to Watt-hours (Wh). Accurately determine the total electrical energy stored in lithium, lead-acid, or solar battery systems using voltage and Ah ratings.
How to Use Ah to Wh Calculator
Converting the Ampere-hour (Ah) rating of a battery into Watt-hours (Wh) provides a clearer understanding of your battery pack's total energy capacity. This is especially useful for solar battery systems, UPS batteries, and RV setups operating at 12V or 24V.
- 1Enter battery capacity. Input the capacity in amp-hours (e.g., 100 Ah) as found on the battery label.
- 2Enter battery voltage. Input the nominal voltage of the battery (e.g., 12 V, 24 V, or 48 V).
- 3View energy capacity. View the total stored energy presented in both watt-hours (Wh) and kilowatt-hours (kWh).
How to Calculate Ah to Wh
To determine the total energy capacity of a battery, you must multiply its electric charge (measured in Amp-hours) by its electric potential (measured in Volts). This calculation applies to lithium batteries, lead-acid batteries, solar battery banks, electric vehicles, and UPS systems.
Amp-hours to Watt-hours Formula
Step-by-step example 1
Let's calculate the energy capacity of a standard 12V deep-cycle battery.
- Battery capacity: 100 Ah
- Voltage: 12 V
Wh = 100 × 12
Wh = 1,200 Wh
Final answer: A 100 Ah battery at 12 V stores 1,200 Wh of energy.
Step-by-step example 2
Let's calculate the energy capacity of a larger 24V battery bank used in an RV or solar setup.
- Battery capacity: 200 Ah
- Voltage: 24 V
Wh = 200 × 24
Wh = 4,800 Wh
Final answer: A 200 Ah battery at 24 V stores 4,800 Wh of energy.
Ah to Wh Chart
The table below provides verified conversions for common battery capacities and voltages found in DC power systems. This helps quickly reference total energy storage across different configurations.
| Battery Capacity (Ah) | Voltage (V) | Energy (Wh) |
|---|---|---|
| 10 Ah | 12 V | 120 Wh |
| 20 Ah | 12 V | 240 Wh |
| 50 Ah | 12 V | 600 Wh |
| 100 Ah | 12 V | 1,200 Wh |
| 50 Ah | 24 V | 1,200 Wh |
| 100 Ah | 24 V | 2,400 Wh |
| 100 Ah | 48 V | 4,800 Wh |
| 200 Ah | 48 V | 9,600 Wh |
Note: Actual usable energy may vary depending on battery chemistry (lithium vs. lead-acid), depth of discharge (DoD), and efficiency losses in the inverter or connected systems.
How to Convert Wh to Ah
Divide the energy in watt-hours by the battery voltage to get its capacity in amp-hours. Use the nominal voltage of the battery, for example 3.7 V per lithium cell or 12.8 V for a 4-cell LiFePO4 pack.
Example: a 1,200 Wh battery at 12 V has 1,200 ÷ 12 = 100 Ah.
| Energy (Wh) | Voltage (V) | Capacity (Ah) |
|---|---|---|
| 100 | 3.70 | 27.03 |
| 500 | 12 | 41.67 |
| 1,200 | 12 | 100.0 |
| 2,400 | 24 | 100.0 |
| 5,000 | 48 | 104.2 |
| 10,000 | 48 | 208.3 |
Ah to Wh Calculator Frequently Asked Questions
Converting Amp-hours to Watt-hours is incredibly simple; you just multiply the battery's Ah rating by its nominal voltage. This critical conversion is necessary because Watt-hours provide a much more accurate representation of the total true energy stored inside your battery than Amp-hours alone.
Amp-hours solely measure electrical charge capacity without considering the electrical pressure. Watt-hours measure the total true energy by factoring in both the capacity and the voltage. Therefore, Watt-hours are universally the best way to compare batteries that operate at different voltage.
A standard 100Ah 12V battery contains approximately twelve hundred Watt-hours of total energy. You calculate this by multiplying the 100 Amp-hours by the 12 Volts. This means the battery could theoretically supply twelve hundred watts of power for one hour, or one hundred watts for twelve hours.
Laptop batteries are typically rated in Watt-hours because they often utilize multiple internal cells wired in different configurations with varying voltages. Using Watt-hours provides consumers with a standardized and highly accurate measurement of the laptop's actual total battery energy capacity.
Watt-hours are generally considered a superior and more useful measurement than Amp-hours when comparing batteries across different systems. Since Wh incorporates the battery voltage, it allows you to easily compare the true energy storage of a 12V system directly against a 24V or 48V battery setup.
The number of Watt-hours (Wh) in an Ampere-hour (Ah) depends directly on system operating voltage, governed by the formula Wh = Ah × Voltage. For example, 1 Ah at 12V equals 12 Wh, whereas 1 Ah at 24V equals 24 Wh, and 1 Ah at 48V equals 48 Wh. Without specifying the nominal battery voltage, an Ampere-hour rating alone cannot be converted into Watt-hours.
