Common Electrical Units
This converter supports commonly used units including:
- Volts (V)
- Amperes (A)
- Ohms (Ω)
- Watts (W)
- Coulombs (C)
- Farads (F)
- Henries (H)
- Siemens (S)
When to Convert Electrical Units
Electrical conversion is useful for electronics, circuit design, electrical engineering, power systems, maintenance, education, and laboratory work. An online converter helps reduce manual calculation errors and makes it easier to compare values expressed in different units.
Electrical Current Conversion FAQ
What is electrical current?
Electrical current is the rate at which electric charge flows through a conductor. It is measured in amperes, commonly called amps, with the unit symbol A.
What is the SI unit of electrical current?
The ampere is the SI base unit of electrical current. Smaller currents are commonly expressed in milliamperes, microamperes, nanoamperes, or picoamperes.
What do A, mA, µA, and nA mean?
- A means ampere.
- mA means milliampere, or one-thousandth of an ampere.
- µA means microampere, or one-millionth of an ampere.
- nA means nanoampere, or one-billionth of an ampere.
Does capitalization matter in electrical unit symbols?
Yes. The symbol for ampere is an uppercase A, while the prefix symbols are case-sensitive. For example, mA means milliampere and MA means megaampere, which is one billion times larger than a milliampere.
What is the difference between current, voltage, resistance, and power?
Current, measured in amperes, is the flow of electric charge. Voltage, measured in volts, is the electrical potential difference. Resistance, measured in ohms, opposes current flow, while power, measured in watts, describes the rate at which electrical energy is transferred.
Can amperes be converted directly to volts, ohms, or watts?
No. These measure different electrical quantities, so a simple unit conversion is not possible. Additional information and an electrical formula such as Ohm's law or the power equation are required.
How do I calculate current using Ohm's law?
For a resistive circuit, divide voltage by resistance: I = V ÷ R. For example, 12 V across a 6 Ω resistance produces a current of 2 A.
How do I calculate current from electrical power?
For a basic DC circuit, divide power by voltage: I = P ÷ V. For example, a 120 W load operating at 12 V draws 10 A under ideal conditions.
Does converting AC amperes to DC amperes require a conversion factor?
No universal conversion factor exists between AC and DC current. Converting the unit from A to mA does not change the type of current, while comparing AC and DC values may require RMS, peak, waveform, rectifier, and efficiency information.
What is the difference between amperes and ampere-hours?
Amperes measure current at a particular moment, while ampere-hours measure electric charge or battery capacity over time. An ampere value cannot be converted directly to ampere-hours without knowing how long the current flows.
How do I convert amperes to ampere-hours?
Multiply the current by the operating time in hours: Ah = A × hours. For example, a current of 2 A flowing for 3 hours represents 6 Ah, assuming the current remains constant.
Why is current sometimes shown in milliamperes instead of amperes?
Using an appropriately sized unit makes a reading easier to understand. A control signal of 0.02 A is more clearly written as 20 mA, while a sensor leakage current of 0.000005 A is more clearly written as 5 µA.
Does unit conversion change measurement accuracy?
No. Converting 2.5 A to 2,500 mA changes only the unit, not the accuracy of the original measurement. Do not report more significant digits than the meter or source data supports.
Why might calculated and measured current differ?
Differences can result from supply-voltage variation, component tolerance, temperature, power factor, motor starting current, changing loads, meter accuracy, waveform distortion, loose connections, or incorrect measurement technique.