# Current Density Calculator

Calculate Current Density
Formula: Current density(J) =
$$\begin{array}{l}\frac{Current (I)}{Area(A)}\end{array}$$

Enter the unknown variable value as ‘x’
Current density(J) =

A/m2
Current(I) =

Ampere(A)
Area(A) =

m2

x =

Current Density Calculator is a free online tool that displays the amount of current that passes per unit area. BYJU’S online current density calculator tool performs the calculation faster and it displays the current density in a fraction of seconds.

## How to Use the Current Density Calculator?

The procedure to use the current density calculator is as follows:

Step 1: Enter the current, area and x for the unknown value in the input field

Step 2: Now click the button “Calculate the Unknown”  to get the current density

Step 3: Finally, the current density of the conductor will be displayed in the output field

### What is Meant by Current Density?

In Physics, the current density is defined as the amount of current that passes through per unit area of the given conductor. The current density is a vector quantity, and it is expressed by the letter “J”. There is a difference between the terms current and current density. The term “current” is defined as the flow of electrons in the conductor, whereas the term “current density” is defined as the flow of electrons in a conductor per unit cross-sectional area. The SI unit of current density is given as Ampere/Meter2. Thus, the formula to calculate the current density is

Current Density = Current (I) / Area (A)

### Solved Example on Current Density

Example 1:

Determine the current density of the copper wire with the area of 20mm2 and the flow of electrons is 10mA current.

Solution:

Given that, current (I) = 10mA = 10×10-3

Area (A) = 20mm2 = 20×10-3

We know that the formula to calculate the current density is:

Current Density = Current / Area

J = (10×10-3)/(20×10-3)

J = 10/20

J=0.5 A/m2

Example 2:

Determine the cross-sectional area of the conductor whose current density is 35 A/m2 and the current is 15 A

Solution:

Given, current density =35 A/m2

Current = 15 A

We know that current density = current/Area

By rearranging the formula, we get

Area = current/ current density

Area = 15/35

Area = 0.429

Hence, the cross-sectional area of the conductor is  0.429m2.