Ratio To Fraction Calculator

Work out ratio to fraction instantly with clear inputs, formula shown and shareable results.

About Ratio To Fraction Calculator

A ratio a : b compares two parts, so the first part is a/(a + b) of the whole. Written as a single fraction the ratio itself is a/b, which is a different quantity from the share of the total.

Formulas

Share of total

first share = a / (a + b)

Ratio as a fraction

a : b = a / b

Worked example

With the default values below, Ratio To Fraction Calculator returns First part as a fraction of the whole of 3/8. Change any input above and every figure here is recalculated in your browser.

Inputs used

First partminimum 0: 3
Second partminimum 0: 5

Results

First part as a fraction of the whole: 3/8
Ratio written as a fraction a/b: 3/5
Decimal share: 0.37500000
Percentage share: 37.5000 %

Step by step

1Values used
2Share of total
3Ratio as a fraction
4First part as a fraction of the whole= 3/8
5Ratio written as a fraction a/b= 3/5
6Decimal share= 0.37500000
7Percentage share= 37.5000 %

Assumptions and limits

The result is derived only from the 2 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 8 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

For 3 : 5?

The first part is 3/8 of the whole (37.5%), while the ratio as a fraction is 3/5.

Which of the two do I want?

Use a/(a+b) when splitting a total, and a/b when comparing the two quantities directly.