Calculate any percentage instantly — what is X% of Y, percentage change, what percent X is of Y, and percentage increase or decrease. Four calculators in one. Free, no signup.
Calculate Percentages
30
20% of 150= 30
20%
30 is 20% of 150
+25%
25% increase+20 difference
230
200 + 15% = 230Change: +30
Quick reference — common percentages of 100:
How to Calculate Percentages
The word "percent" comes from the Latin per centum, meaning "per hundred." A percentage is simply a number expressed as a fraction of 100. Understanding the three core percentage formulas covers 95% of all real-world percentage problems:
1. What is P% of N? → Result = N × (P / 100)
2. X is what % of Y? → Result = (X / Y) × 100
3. % Change → Result = ((New - Old) / Old) × 100
Real-world percentage examples
Sales tax: $45 item with 8% tax → 45 × 0.08 = $3.60 tax → $48.60 total
Tip calculation: 20% tip on $65 bill → 65 × 0.20 = $13 tip
Discount: 30% off $120 → 120 × 0.30 = $36 off → $84 final price
Grade: 42 correct out of 50 → (42/50) × 100 = 84%
Pay raise: Salary goes from $55,000 to $60,000 → ((60000-55000)/55000) × 100 = 9.09% raise
Percentage Increase vs Percentage Points
One of the most common confusions in percentages is the difference between a "percentage change" and a "percentage point change." These are completely different things:
Percentage points: The arithmetic difference between two percentages. If interest rates go from 2% to 5%, that's a 3 percentage point increase.
Percentage change: The relative change. Going from 2% to 5% is a 150% increase (because 5 is 150% more than 2).
Politicians and media often use these interchangeably — usually choosing whichever makes a change seem larger or smaller depending on their argument. Knowing the difference protects you from being misled.
How to calculate percentage of a percentage
If a product costs $200, is on sale for 20% off, and you also have a 10% coupon, the discounts do NOT simply add to 30%. You calculate them sequentially: $200 − 20% = $160, then $160 − 10% = $144. Total saving: $56, or 28% — not 30%.
Frequently Asked Questions
What is 15% of 200?
15% of 200 = 200 × (15/100) = 30. A quick mental math trick: 10% of 200 is 20, half of that (5%) is 10, add them: 20 + 10 = 30.
How do I calculate a percentage on a calculator?
For "X% of Y": type Y × X ÷ 100 =. For percentage change: type (New − Old) ÷ Old × 100 =. Most phone calculators also have a % button: type Y × X% to get X% of Y directly.
How do I calculate a 20% tip quickly?
Move the decimal one place left to get 10%, then double it. $65 bill: 10% = $6.50, double = $13.00 tip. For 15%: find 10%, find 5% (half of 10%), add them together.
What is the formula for percentage difference?
Percentage difference = |V1 − V2| / ((V1 + V2) / 2) × 100. This is used when comparing two values without a clear "old" and "new" — for example, comparing prices between two stores. It gives the difference relative to the average of the two values.