Can percentage change be negative?

Yes. A negative percentage change indicates a decrease. For example, going from 200 to 150 is a -25% change. The calculator clearly labels results as 'increase' or 'decrease'.

Why is a 50% increase followed by a 50% decrease not back to the original?

Because each percentage is calculated from a different base. A 50% increase on 100 gives 150. A 50% decrease on 150 gives 75 — not 100. The second 50% is applied to the larger number. This is why you need a 33.3% decrease to reverse a 50% increase.

How do I calculate a tip?

Use the 'X% of Y' mode. Enter the tip percentage (e.g., 20) and the bill amount (e.g., 85). The calculator will show that 20% of $85 is $17, making your total $102.

How do I find what percentage one number is of another?

Use the 'X is what % of Y' mode. For example, to find what percentage 35 is of 200, enter 35 and 200. The calculator shows that 35 is 17.5% of 200.

What's the difference between percentage and percentage points?

Percentage points measure absolute difference, while percentage measures relative change. If interest rates go from 3% to 5%, that's a 2 percentage point increase but a 66.7% relative increase (2/3 × 100).

How do I calculate what percentage was removed during a sale?

Use percentage change mode. Enter the original price as 'old value' and sale price as 'new value'. A $100 item on sale for $75 shows a -25% change, meaning 25% off.

Can percentages exceed 100%?

Yes. Percentage change can exceed 100% (e.g., doubling is a 100% increase, tripling is 200%). 'X is what % of Y' can also exceed 100% when X is larger than Y (150 is 300% of 50).

general

Percentage Calculator

Calculate percentages three ways: find X% of a number, what percent X is of Y, or percentage change between two values. Free, instant results.

Last updated: March 31, 2026

What is X% of Y?

Percentage

Of value

How to Use This Calculator

Choose your calculation mode: 'X% of Y', 'X is what % of Y', or 'Percentage change'.
Enter the required values in the input fields.
Click Calculate to see the result instantly.
Review the step-by-step breakdown showing how the calculation was performed.

Real-World Examples

Restaurant Tip Calculation

Your dinner bill is $78.50. You want to leave an 18% tip.

Result: 18% of $78.50 = $14.13. Total with tip: $92.63. Round up to $93 for easy payment.

Test Score Percentage

You got 47 questions correct out of 60 total questions on an exam.

Result: 47 is 78.33% of 60. This equals a C+ or B- depending on your school's grading scale.

Stock Price Change

A stock price increased from $45.00 to $52.50 over the quarter.

Result: Percentage change: +16.67% increase. Your $1,000 investment is now worth $1,166.70.

Common Mistakes to Avoid

Dividing by the new value instead of the old value when calculating percentage change.
Adding percentages directly (20% + 10% ≠ 30% off) — they compound, not add.
Confusing 'percentage of' with 'percentage points' (going from 20% to 25% is a 5 percentage point increase, but a 25% relative increase).
Forgetting to multiply by 100 when converting a decimal to a percentage (0.15 = 15%, not 0.15%).

The Formula

Mode 1: Result = (Percentage / 100) x Number. Mode 2: Percentage = (Part / Whole) x 100. Mode 3: Change = ((New - Old) / Old) x 100.

Learn More

Math

How to Calculate Percentage: 3 Methods Anyone Can Use

Three simple methods for percentages: of a number, between values, and change.

April 3, 2026

Frequently Asked Questions

'Percentage of' finds a portion of a number (e.g., 20% of 150 = 30). 'Percentage change' measures how much a value increased or decreased relative to its original value (e.g., from 100 to 150 is a 50% increase).