Percentage Calculator
Calculate percentages, increases, decreases, and percentage differences instantly.
Percentage details
Choose the percentage calculation type and enter the values.
The percentage to calculate.
The number to take a percentage of.
Result
30
What is X% of Y?
Equation
200 × 15 ÷ 100 = 30
Calculated from your current inputs.
Number
200
Percentage
15%
Decimal form
0.15
Fraction form
3/20
Result actions
Save the current calculation
Copy the result, copy only the equation, or save this calculation to the short history list.
Interpretation
What this percentage result means
15% of 200 is 30.
Steps
Calculation steps
- 1Convert 15% to a decimal: 15 ÷ 100 = 0.15.
- 2Multiply 200 by 0.15.
- 3Result: 30.
Percentage basics
Common percentage calculations
Percent of a number
Use this when you need a share, such as 15% of 200.
Part vs whole
Compare one number against another to find its percentage share.
Increase or decrease
Measure how much a value changed compared with its original value.
Discounts and tax
Add or subtract percentages for shopping, tax, margins, and price changes.
Formula
Percentage formula explanation
Part formula
Part = Whole × Percentage ÷ 100Use this to find a percentage of a number.
Percentage formula
Percentage = Part ÷ Whole × 100Use this to find what percent one value is of another.
Change formula
Change % = (New − Original) ÷ Original × 100Use this to measure percentage increase or decrease.
Use cases
Where percentage calculators help
Shopping discounts
Calculate sale prices, amount saved, taxes, tips, and markups.
Grades and scores
Convert marks, correct answers, or totals into percentage scores.
Growth and decline
Compare old and new values for business, traffic, finance, or fitness.
Reverse percentages
Work backward from a final value to estimate the original value.
Ratios and shares
Find how large one value is compared with a reference total.
Everyday math
Quickly solve percentage questions without writing formulas manually.
Trust
About this estimate
Transparent method
Shows the formula, equation, steps, and final answer for the selected percentage type.
Unit-free results
Percentages work with money, scores, counts, prices, or measurements when units are used consistently.
Easy comparison
Switch calculation types or reset values to test different percentage scenarios quickly.
FAQ
Percentage calculator questions
Multiply the number by the percentage, then divide by 100. For example, 20% of 80 is 80 × 20 ÷ 100 = 16.
The core formula is Part = Whole × Percentage ÷ 100. You can rearrange it to find the percentage or the whole.
Divide the part by the whole, then multiply by 100. For example, 25 out of 200 is 25 ÷ 200 × 100 = 12.5%.
Subtract the original value from the new value, divide by the original value, then multiply by 100.
Multiply the original price by the discount percentage to get the amount off, then subtract that amount from the original price.
Divide the final value by 1 plus the percentage rate as a decimal. For example, after a 20% increase, divide by 1.20.
Divide the final value by 1 minus the percentage rate as a decimal. For example, after a 20% decrease, divide by 0.80.
Percentage points measure the direct difference between two percentages. Percent change compares that difference relative to the starting value.
They use different bases. A 10% increase followed by a 10% decrease leaves you below the starting value because the decrease is applied to the higher amount.
Yes, but percentage interpretation can be less intuitive with negative bases. For everyday finance, shopping, grades, and ratios, positive values are usually clearer.
Related reading
Learn the formula, assumptions, examples, or context behind this tool.