About the Percentage Calculator
This Percentage Calculator helps you work confidently with percentages in everyday scenarios—discounts and markups while shopping, taxes and tips on bills, exam scores, interest growth, and changes in data over time. Because percentages express a number as a fraction of 100, they make comparisons clear and intuitive across different scales (for example, 20% of 50 vs. 20% of 500). Our calculator consolidates the most common percentage operations into simple tabs so you can find the right method instantly.
Use the Basic tab to find X% of Y; the Increase and Decrease tabs to apply a percentage change to an original value; and the Change tab to compute the percentage difference between two numbers. These cover the majority of real‑world needs—from calculating a 15% tip to adjusting prices by a target margin, to analyzing how much a metric moved month‑over‑month. Each operation follows the standard formulas shown below and produces results you can trust.
A common pitfall is confusing percent and percentage points: moving from 10% to 12% is an increase of 2 percentage points, which is a 20% relative increase. Another is reversing a percentage change: after a +25% increase, you cannot return to the original value by simply decreasing by 25%; instead, divide by 1.25. Our examples and FAQ address these patterns so your calculations remain accurate.
Key features
- Covers % of a number, percentage increase/decrease, and percent change
- Clear formulas with inline examples for learning and verification
- Great for shopping, budgeting, reporting, and academic practice
- Mobile‑friendly UI designed for quick, error‑free entry
How to use
- Choose a tab: Basic %, Increase, Decrease, or Change.
- Enter your numbers in the input fields.
- Read the result and explanation instantly.
Formula
Basic: X% of Y = (X ÷ 100) × Y; Increase: New = Original × (1 + X/100); Decrease: New = Original × (1 − X/100); Change: ((New − Original) ÷ Original) × 100
Variables
| Symbol | Meaning |
|---|---|
| X | Percentage value to apply (e.g., 15 for 15%) |
| Y / Original | Base or starting number before applying the percentage |
| New | Result after applying a percentage increase or decrease |
Examples
- 12% of 350 → (12 ÷ 100) × 350 = 42
- Increase 480 by 7% → 480 × 1.07 = 513.6
- Decrease 80 by 15% → 80 × 0.85 = 68
- Change from 150 to 180 → ((180 − 150) ÷ 150) × 100 = 20%
Tips
- When stacking changes, multiply the factors (e.g., +10% then −5% → ×1.10 ×0.95).
- Use percentage points when comparing rates (e.g., 12% vs 10%).
- Convert percent to decimal for calculations: X% → X ÷ 100.