Percentage Calculator Australia 2026-27

GlobalCalc

Inputs

Question

The percentage (first question) or the first number

The number the percentage applies to, or the second number

Results update as you type

Results

Answer

Working—

Reverse question—

As a decimal fraction—

Reviewed September 2026. Pure mathematics: the result does not depend on where you are. Terminology follows the Australian Curriculum (maths, brackets, decimal point).

All calculations run 100% in your browser. The calculator code does not submit your figures to GlobalCalc to obtain a result.

About percentage

Method

How the percentage calculator works

A percentage is a fraction of 100. "X% of Y" is Y × X ÷ 100; "X is what percent of Y" is X ÷ Y × 100; and the percentage change from A to B is (B − A) ÷ A × 100, positive for an increase and negative for a decrease. Choose the question, enter the two numbers, and the answer, the working and the reverse question update as you type.

Formula: X% of Y = Y × X / 100; X as % of Y = X / Y × 100; change = (B − A) / A × 100

Data

Worked examples

Inputs	Answer	Note
15% of 240	36	240 × 0.15
36 is what % of 240	15%	36 ÷ 240 × 100
Change from 80 to 100	+25%	(100 − 80) ÷ 80
Change from 100 to 80	-20%	a decrease — the same 20 is −20% here

FAQ

Frequently asked questions

How do I work out a percentage of a number?

Multiply the number by the percentage and divide by 100. 15% of 240 is 240 × 15 ÷ 100 = 36.

How do I find what percentage one number is of another?

Divide the part by the whole and multiply by 100. 36 of 240 is 36 ÷ 240 × 100 = 15%.

Why is a 20% rise followed by a 20% fall not back to the start?

Because the fall is 20% of the larger number. 100 → 120 → 96. Percentage changes compound; they do not simply add.

What is the difference between percentage points and percent?

Going from 10% to 15% is a rise of 5 percentage points but a 50% increase in the rate.

How do I add a percentage to a price?

Multiply by (1 + rate). Adding 10% to 50 is 50 × 1.10 = 55; removing 10% from 55 is 55 ÷ 1.10 = 50, not 55 × 0.90.

Sources

Where these figures come from

NIST Digital Library of Mathematical Functions — reference definitions for elementary and special functions
Wolfram MathWorld — definitions and formulas for every topic on this page
NIST/SEMATECH e-Handbook of Statistical Methods — the statistical formulas (mean, variance, z, confidence intervals, sample size)
Australian Curriculum (ACARA) — Mathematics — the terms and methods taught in Australian schools

Last checked: September 2026. Formulas are fixed by mathematics and do not change with tax years or regulations.