Current Calculator
Use the current calculator below to calculate amps given the voltage, power, or resistance.
Enter any two of the following values to calculate the electric current.
Electric current (I) is the flow of electric charge through a conductor, measured in amperes (A).
If you already know the current, enter it here. Otherwise, provide two other parameters to calculate it.
Current Calculation Formulas
I = V / R
From voltage and resistance
I = P / V
From power and voltage
I = √(P / R)
From power and resistance
Note: The calculator automatically determines which formula to use based on your inputs.
About Electric Current
What is Electric Current?
Electric current is the flow of electric charge through a conductor. The SI unit of electric current is the ampere (A).
How to Use the Current Calculator
Enter any two values of voltage, resistance, or power to calculate the current.
Current Calculation Formulas
The current can be calculated using various formulas depending on the known parameters.
Applications of Current Calculations
Current calculations are important in various areas like electronics design, electrical engineering, and safety measures.
Frequently Asked Questions
Find answers to common questions about electric current and using the current calculator.
What is Electric Current?
Electric current is the rate of flow of electric charge past a given point in an electric circuit, measured in amperes (A). The moving charged particles are typically electrons in metal conductors, though they can be other charged particles in different circumstances.
Definition of Current
Electric current is defined as the rate at which electric charge flows past a point in a circuit. Mathematically, it is expressed as I = Q/t, where I is current in amperes, Q is the electric charge in coulombs, and t is time in seconds.
Unit of Measurement
The standard unit for measuring electric current is the ampere (A), named after André-Marie Ampère. One ampere represents one coulomb of electric charge moving past a specific point in one second. Smaller units include milliampere (mA) and microampere (μA).
Key Concepts Related to Current
- Current (I): The rate of flow of electric charge, measured in amperes (A).
- Voltage (V): The electric potential difference that drives current flow, measured in volts (V).
- Resistance (R): The opposition to current flow in a circuit, measured in ohms (Ω).
- Power (P): The rate at which energy is transferred or converted, measured in watts (W).
Historical Background
The concept of electric current was developed in the late 18th and early 19th centuries. André-Marie Ampère made significant contributions to our understanding of electric current in the 1820s, establishing the relationship between electricity and magnetism.