Percentage Difference Calculator
Compares two values relative to their average.
Result
- Percentage difference
- 22.22%
How to use the percentage difference calculator
- Enter the value a.
- Enter the value b.
- The results update as you type, or press Calculate.
- Read the percentage difference first, then the supporting figures below it.
Formula
% diff = |A − B| ÷ ((A + B) ÷ 2) × 100.
Worked example
For example, with these inputs:
- Value A: 40
- Value B: 50
the calculator returns:
- Percentage difference: 22.22%
Background
These calculations appear throughout the Singapore syllabus, from primary school percentages and fractions to secondary school algebra and geometry. Understanding the formula makes problem sums easier because you can recognise which quantity is missing.
Rounding is a common source of small errors. Keep full precision during intermediate steps and round only the final answer to the number of decimal places or significant figures the question asks for.
Frequently asked questions
How does the percentage difference calculator work?
It applies this formula: % diff = |A − B| ÷ ((A + B) ÷ 2) × 100.
Can I use any units?
Yes, as long as every input uses the same unit. The answer will be in that unit (squared for areas, cubed for volumes).