How to Calculate Percentages: The Complete Guide
Master every kind of percentage problem — finding a percentage of a number, percentage change, increases and decreases, working backwards, and the traps that catch people out — with clear examples.
Percentage Difference Calculator
Verified formula Updated Jun 2026 Private — runs on your device
Verified formula
Private
Percentage difference
22.22%
- Absolute difference
- 20.00
- Average of the two
- 90.00
For general information only — not financial, tax, legal or medical advice. Verify before you rely on it.
How to use the Percentage Difference Calculator
The Percentage Difference Calculator works out your percentage difference, along with 2 related figures in an instant. Enter first value and second value and the result updates as you type — it is free, needs no sign-up, and runs entirely in your browser so your figures stay private.
- Enter the first value.
- Enter the second value.
- Read off your percentage difference, together with absolute difference and average of the two — the calculator updates automatically, with no button to press.
Worked example
For example, with first value of 80 and second value of 100, the percentage difference is 22.22%.
| First value | 80 |
|---|---|
| Second value | 100 |
| Percentage difference | 22.22% |
|---|---|
| Absolute difference | 20.00 |
| Average of the two | 90.00 |
Results are estimates for educational use, not professional advice.
Key terms explained
- Percentage
- A number expressed as a fraction of 100, written with the % sign.
- Mean
- The average of a set of numbers — their sum divided by how many there are.
Frequently asked questions
It compares two values relative to their average: take the absolute difference, divide by the average of the two and multiply by 100. For 80 and 100 it is 20 ÷ 90 × 100 = 22.22%.
Percentage change has a clear start and end and uses the original value as the base. Percentage difference compares two values with no order, using their average as the base.
No. Because it uses the absolute difference, it is always zero or positive — it measures how far apart the values are, not which is bigger.
Use it when neither value is the obvious reference point, such as comparing two measurements or two readings of the same kind.
Enter the first value. Enter the second value. Read off your percentage difference, together with absolute difference and average of the two — the calculator updates automatically, with no button to press.
Related guides
Percentage Difference Table: Percentage difference by First value
Reference table of percentage difference for Percentage Difference across a range of first value values — exact, engine-computed figures you can read off at a glance.
How to Calculate Percentage Difference: Formula, Steps & Examples
Learn how to calculate Percentage Difference — the formula explained step by step, with worked examples and a free calculator to check your answer.