Direct Variation Calculator

Direct Variation Calculator is a free online tool that displays the solution of the unknown variables which are directly proportional to each other. BYJU’S online direct variation calculator tool makes the calculation faster and also it displays the variable value in a fraction of seconds.

How to Use the Direct Variation Calculator? 

The procedure to use the direct variation calculator is as follows:

Step 1: Enter the known values in the input field

Step 2: Now click the button “Solve” to get the variable value

Step 3: Finally, the solution of the unknown variable will be displayed in the output field

What is Meant by Direct Variation?

Direct variation calculator helps to solve for variables which are directly proportional to each other.

If two quantities are directly proportional, the increase in one quantity will result in an increase in the other quantity.

If two quantities (x and y) are directly proportional to each other, then, they are represented as follows:

x ∝ y

If a proportionality constant is put, then the direct variation formula is given as,

x = ky

Or, x/y = k

Here, “k” is the constant of proportionality. This equation represents that when two directly proportional quantities are divided, the resultant value is always a constant.


Question: If the cost of 10 pens are Rs. 100, calculate the cost of 30 pens.


Here, the cost of pens ∝ total number of pens.

Thus, the cost of pens/total number of pens = constant

Now, let the cost of 30 pens be Rs. “x”

Consider the first case,

10 pens cost = Rs. 100 and

30 pens cost = Rs. x

So, 10/ 100 = 30/x

Or, x = 300.