# Direct Variation Calculator

Direct variation exists between any two variables when one quantity is directly dependent on the other i.e. if one quantity increases with respect to the other quantity and vice versa. It is the relationship between two variables where one of the variables is a constant multiple of the other.

## What is a Direct Variation Calculator?

A 'Direct Variation Calculator' is a free online tool that calculates the unknown variable of two directly proportional quantities. In this calculator, you can enter the known terms and the unknown term will be calculated within a few seconds.

NOTE: Enter the values up to three digits only.

## How to Use Direct Variation Calculator?

Follow the steps given below to use the calculator:

**Step 1:**Enter the known values of y and x.**Step 2:**Click on**"Calculate"**to know the value of 'k' constant.**Step 3:**Click on**"Reset"**to clear the field and enter new values.

## How to Find the Constant Value in Direct Variation?

Let's consider two variables x and y. If the quantity y is directly varying with respect to the quantity x i.e, y ∝ x, then the direct variation formula is given by:

**y = kx**

Where k is the constant of proportionality.

Since the variables y and x are in a directly proportional relationship, their ratio is always a constant number i.e, k.

Thus, y/x = k

Let's say y1 directly varies with x1 and y2 directly varies with x2 then, the direct variation formula is given by:

**(y _{1} / x_{1}) = (y_{2} / x_{2})**

**Solved Example:**

If the cost of 4 lego models is $640 then what will be the cost for one such model?

**Solution:**

Cost of 4 lego models = $640

Here,

x = 4

y = 640

Now, the direct variation formula

y = kx

k = y/x

k = 640/4

k = 160

Thus, the cost for one lego model will be $160