Percentage Calculator
Calculate percentages in four common scenarios: X% of Y, X as a percentage of Y, percentage change and percentage difference — live results, a common-percentages table and step-by-step formulas.
Example values are shown — change any of them and the answer updates live.
What is % of ?
25% of 160 is 40.
| Portion of Y | 40 |
| Remaining | 120 |
| Ratio | 25 : 75 |
X% → X ÷ 10025 ÷ 100 = 0.250.25(X ÷ 100) × Y0.25 × 160 = 4040| 1% of 160 | 1.6 |
| 5% of 160 | 8 |
| 10% of 160 | 16 |
| 15% of 160 | 24 |
| 20% of 160 | 32 |
| 25% of 160 | 40 |
| 50% of 160 | 80 |
| 75% of 160 | 120 |
| 100% of 160 | 160 |
What is a percentage?
A percentage expresses a number as a fraction of 100. "25%" means 25 out of every 100. Percentages make comparisons across different-sized groups readable: a 15% rate means the same relative size whether the base is 200 or 2,000,000.
Percentage change vs percentage difference
Percentage change measures growth or decline over time: (new − old) ÷ |old| × 100. A price going from 80 to 100 is a +25% change. Percentage difference compares two values of the same kind without a time direction: |a − b| ÷ ((a + b) ÷ 2) × 100. For 80 and 100 the difference is 22.2% of their average — use change for before/after, difference for side-by-side comparison.
The formulas
X% of Y = X × Y ÷ 100. X is what percent of Y: X ÷ Y × 100. Percent change: (new − old) ÷ |old| × 100 (negative means decrease). Percent difference: |a − b| ÷ ((a + b) ÷ 2) × 100.
Worked examples
Example 1: 25% of 160 = 25 × 160 ÷ 100 = 40. Example 2: 48 is what percent of 200? 48 ÷ 200 × 100 = 24%. Example 3: sales rise from 1,200 to 1,500: (1500 − 1200) ÷ 1200 × 100 = +25%.
Limitations
Percentages describe relative size only — always note the base. A "50% increase" from a small base can be smaller in absolute terms than a "5% increase" from a large one. Percentage change cannot be calculated when the old value is zero; percentage difference cannot be calculated when both values are zero.
Compare scenarios
Before
Baseline
After
New value
Exact arithmetic — computed instantly in your browser.