Percentage Calculator
Calculate percentages instantly — find X% of a number, what percentage one number is of another, or the percentage change between two values.
How to Use the Percentage Calculator
Choose the tab that matches your question:
- X% of Y — Enter a percentage and a value to find the portion (e.g., 15% of 200 = 30).
- X is ?% of Y — Enter a part and a whole to find what percentage the part represents.
- % Change — Enter a starting value and an ending value to find the percentage increase or decrease.
The Extended Calculator below adds Increase/Decrease analysis, Proportion solving, and a Tip calculator with a visual percentage bar. The Professional Calculator handles compound percentages, sequential percentage chains, and batch calculations.
Percentage Formulas
Find X% of Y: Result = (X ÷ 100) × Y
X is what % of Y: Percentage = (X ÷ Y) × 100
Percentage Change: Change % = ((New − Old) ÷ |Old|) × 100
Find Original (reverse %): Original = Result ÷ (Percentage ÷ 100)
Compound Percentage: Final = Start × (1 + r/100)ⁿ
Worked Example
Example 1: What is 20% of 450?
(20 ÷ 100) × 450 = 0.20 × 450 = 90
Example 2: 75 is what % of 300?
(75 ÷ 300) × 100 = 25%
Example 3: Price went from R120 to R150 — what is the % increase?
((150 − 120) ÷ 120) × 100 = 25% increase
Example 4 (compound): R1,000 grows at 8% p.a. for 3 years:
1000 × 1.08³ = 1000 × 1.2597 = R1,259.71
Period-by-Period Table
| Period | Value | Change |
|---|---|---|
| 1 | 1 050 | +50 |
| 2 | 1 102,5 | +52,5 |
| 3 | 1 157,63 | +55,13 |
| 4 | 1 215,51 | +57,88 |
| 5 | 1 276,28 | +60,78 |
| 6 | 1 340,1 | +63,81 |
| 7 | 1 407,1 | +67 |
| 8 | 1 477,46 | +70,36 |
| 9 | 1 551,33 | +73,87 |
| 10 | 1 628,89 | +77,57 |