Capacitance to mAh Calculator
Evaluate the nominal stored electric charge in milliampere-hours (mAh) equivalent to a capacitor given its capacitance (C) and voltage (V). Compare supercapacitors to battery grids dynamically.
Capacitance to mAh Calculator
How to Use the Capacitance to mAh Calculator
Calculating the equivalent battery capacity in milliampere-hours (mAh) is straightforward. Follow these steps:
- 1Enter Capacitance: Input the rated capacitance value of the capacitor.
- 2Select Capacitance Unit: Choose Farad (F), millifarad (mF), or microfarad (µF).
- 3Enter Voltage: Input the terminal operating voltage.
- 4Select Voltage Unit: Choose Volt (V) or millivolt (mV).
- 5Calculate: Click the "Calculate to mAh" button to run the conversion.
How to Calculate Capacitance to mAh
In electronics and backup power systems, capacitors store charge. The quantity of charge (Q) in Coulombs is the product of capacitance (C) in Farads and voltage (V) in Volts. Milliampere-hours (mAh) is a unit of electrical charge commonly used to define battery capacity. Since 1 Coulomb is equivalent to 1 Ampere-second, dividing the charge in Coulombs by 3.6 yields the capacity in mAh. Sizing backup nodes, solar accumulators, or supercapacitor banks requires converting capacitance to mAh.
Real-Life Sizing Scenarios
Scenario 1: Sizing Equivalent mAh Sizing for a 50 F Supercapacitor at 12 V
An electrical technician calculates the equivalent capacity of a 50 Farad supercapacitor operating in a 12 V backup generator memory circuit:
Q_mah = (C × V × 1000) ÷ 3600 = (50 F × 12 V × 1000) ÷ 3600 = 166.67 mAh
Scenario 2: Sizing Equivalent mAh Sizing for a 1 F Low-Voltage backup at 5.5 V
A hardware engineer calculates the backup capacity of a 1 Farad supercapacitor rated for 5.5 V operating in a microcontroller memory retention path:
Q_mah = (C × V × 1000) ÷ 3600 = (1 F × 5.5 V × 1000) ÷ 3600 = 1.53 mAh
Step-by-Step Manual Sizing Guide
- 1Identify circuit parameters: Settle the capacitance (C) and the voltage (V).
- 2Scale to base physical units: Convert capacitance to Farads (F) (e.g. 500 mF = 0.5 F) and voltage to Volts (V).
- 3Solve the capacity quotient: Apply the formula:
Q_mah = (C × V × 1000) ÷ 3600to compute capacity in mAh.
Capacitance to mAh Chart
The table below displays typical capacitance values and their corresponding stored charge in Coulombs (C) and equivalent battery capacity in mAh calculated at standard voltages (5 V and 12 V):
| Capacitance Input | Voltage Level | Stored Charge (Coulombs) | Equivalent Capacity (mAh) |
|---|---|---|---|
| 1 F | 5 V / 12 V | 5 C / 12 C | 1.39 mAh / 3.33 mAh |
| 5 F | 5 V / 12 V | 25 C / 60 C | 6.94 mAh / 16.67 mAh |
| 10 F | 5 V / 12 V | 50 C / 120 C | 13.89 mAh / 33.33 mAh |
| 25 F | 5 V / 12 V | 125 C / 300 C | 34.72 mAh / 83.33 mAh |
| 50 F | 5 V / 12 V | 250 C / 600 C | 69.44 mAh / 166.67 mAh |
| 100 F | 5 V / 12 V | 500 C / 1200 C | 138.89 mAh / 333.33 mAh |
| 250 F | 5 V / 12 V | 1250 C / 3000 C | 347.22 mAh / 833.33 mAh |
| 500 F | 5 V / 12 V | 2500 C / 6000 C | 694.44 mAh / 1666.67 mAh |
Frequently Asked Questions (FAQs)
To convert capacitance (in Farads) and voltage (in Volts) to milliampere-hours (mAh), use the conversion formula:
Q_mah = (C × V × 1000) ÷ 3600 = (C × V) ÷ 3.6.
Yes, in short-term backup or memory retention paths supercapacitors can replace batteries. However, batteries hold much higher energy densities and maintain flatter voltage curves, whereas capacitors discharge with a linear voltage drop.
Substitute the parameters into the equation:
Q_mah = (10 F × 12 V) ÷ 3.6 = 33.33 mAh.
One Ampere-hour (Ah) represents 3,600 Coulombs of charge. Stored charge in Coulombs is C × V, so the equivalent capacity in Ampere-hours is: Q_ah = (C × V) ÷ 3600.
Yes. Stored charge increases linearly with terminal operating voltage. Higher voltages allow the same physical capacitor to hold more charge, resulting in a higher equivalent mAh rating.
