Home » Simplify your calculations with ease. » Electrical » Inrush Calculator Online

# Inrush Calculator Online

The Inrush Calculator is a valuable tool used in electrical engineering to estimate the initial surge of current when an electrical circuit or device is turned on. This surge, known as inrush current, occurs due to the sudden demand for electrical power when capacitors charge or due to the magnetizing of inductors.

## Formula of Inrush Calculator

The formula to calculate inrush current (`Iinrush`) using the Inrush Calculator is given by:

`Iinrush = (V / R) * (1 - e^(-t / τ))`

Where:

• `Iinrush` is the inrush current (initial current).
• `V` is the voltage across the circuit or device (in volts, V).
• `R` is the resistance of the circuit or device (in ohms, Ω).
• `t` is the time in seconds (s).
• `τ` (tau) is the time constant of the circuit, which is equal to `L / R`, where `L` is the inductance of the circuit (in henrys, H).

## Table of General Terms

Here’s a table of commonly used terms related to inrush current:

## Example of Inrush Calculator

Consider a circuit with a voltage of 12V, a resistance of 100Ω, a time duration of 5 seconds, and an inductance of 0.2H. Using the Inrush Calculator, we can determine the inrush current by substituting these values into the formula:

`Iinrush = (12 / 100) * (1 - e^(-5 / (0.2 / 100)))`