# Direct Proportion Calculator

A simple online direct proportion calculator to find the unknown value using the Rule of Three Direct Proportion method. Enter the values for the known values of 3 numbers in this rule of three calculator and click calculate to find the value of the unknown number.

A simple online direct proportion calculator to find the unknown value using the Rule of Three Direct Proportion method. Enter the values for the known values of 3 numbers in this rule of three calculator and click calculate to find the value of the unknown number.

Code to add this calci to your website

#### Formula:

y = (b × x) / a
**Where,**
a = Value of a
b = Value of b
x = New Value of a
y = New Value of b
**Rule of Three:** This rule is a method to solve proportions, which is defined as, if you have three numbers a, b, c, such that, a/b = c/x, also represented as a:b::c:x, then you can calculate the unknown value x, using the other three known values.

**Direct Proportion**: Direct proportion means that any increase in the known values increases the unknown value at the same rate

**Direct Proportion Calculator:** Here is an online **Rule of three calculator** for you to calculate the value of Y based on the **Rule of three direct proportionate method**. Just input the values for reliable results. For manual calculation, you can just divide products of value of 'b' and new value of 'a' by the value of 'a'

### Example:

If I have 8 litres of milk to serve 2 families, then how many families I would need to 16 litres of milk?

#### Solution

Direct Proportion = 8 : 2

= 16 : ?

Applying the rule of three,

= 2 x 16 / 8

= 32 / 8

= 4 families