Percentage Calculator
Instantly solve percentage problems. From calculating parts of a whole to exploring percentage increases and decreases.
How to Calculate Percentages & Mathematical Formulas
A percentage is simply a number out of 100. Learning how to calculate percentages is essential for students, business owners, and everyday shopping. The word "percent" means "per hundred" in Latin. It is a way of expressing a fraction with a denominator of 100, which makes it easier to compare different values.
What is X% of Y? (Calculating parts)
This is used to find a specific part of a whole. To find the amount, you multiply the total value (Y) by the percentage (X), then divide that result by 100. This is how you calculate tax or tips.
| Question | Calculation | Answer |
|---|---|---|
| What is 10% of 50? | 50 × 0.10 | 5 |
| What is 25% of 200? | 200 × 0.25 | 50 |
| What is 8% of 1200? | 1200 × 0.08 | 96 |
X is what % of Y?
This helps you determine how much a specific number represents as a portion of another. You divide the part (X) by the total (Y) and multiply the result by 100 to get the percentage value.
| Question | Calculation | Answer |
|---|---|---|
| 30 is what % of 150? | (30 ÷ 150) × 100 | 20% |
| 7 is what % of 28? | (7 ÷ 28) × 100 | 25% |
| 45 is what % of 90? | (45 ÷ 90) × 100 | 50% |
What is the Percentage Change?
Used to calculate the increase or decrease between two values. Subtract the old value from the new one, divide by the absolute value of the old one, and then multiply by 100.
| Question | Calculation | Answer |
|---|---|---|
| From 80 to 100 | ((100 - 80) ÷ 80) × 100 | +25% increase |
| From 200 to 150 | ((150 - 200) ÷ 200) × 100 | -25% decrease |
| From 40 to 40 | ((40 - 40) ÷ 40) × 100 | 0% no change |
Everyday Examples
🛒 Shopping sale
A jacket costs €80 but is 20% off. You save €16. Final price = €64.
🧾 VAT / Sales tax
Price is €100, VAT is 23%. Tax = €23. Total = €123.
📈 Salary raise
Earn €3,000/month, get 5% raise. Raise = €150. New salary = €3,150.
🏦 Bank interest
€10,000 in savings at 4% per year. Interest = €400/year.
🛒 Price increase
Coffee was €2.50, now €2.80. Increase = 12%.
📊 Exam score
Got 42 out of 56 questions right. Score = 75%.
Key Percentage Terms
Percentage Increase
The relative increase of a value expressed as a percentage of the original amount.
Profit Margin
The difference between revenue and cost, expressed as a percent of the revenue.
Reverse Percentage
Finding the original value after a percentage increase or decrease has been applied.