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Percentage workspace
(new − original) ÷ original × 100
Share this exact calculation with values pre-filled.
FREE PERCENTAGE CALCULATOR
Percentage increase, decrease, reverse percentage, markup, and margin.
Choose a percentage question, enter the values, and see the result with the formula used. This page is built for common questions like how to find percentage increase, percentage decrease, percent of a number, reverse discount, markup, and profit margin.10 modes
TRY REAL QUESTIONS
Common percentage examples
These examples answer the kinds of queries users search for, while keeping the calculator inputs clear and editable.WHAT IT SOLVES
Use one calculator for everyday percentage questions
Percentage increase and decreasePercent of a numberPart as a percentage of wholeReverse percentage and original priceMarkup, margin, and compound growthShareable calculation links
HOW TO USE
Choose the problem before entering numbers
- Select the calculation type that matches the wording of your question.
- Enter the original value and new value, or part and whole, depending on the mode.
- Check the formula line to confirm the correct base value is being used.
- Copy the share link when you want to reopen the same calculation later.
FORMULAS
Percentage formulas with simple meaning
Percentage problems often go wrong because the wrong base value is used. These notes show which value should be compared.Percentage increase formula
(new value − original value) ÷ original value × 100Use this when a value goes up, for example from 80 to 100. The original value is the base, so the increase is compared with 80, not with 100.
Percentage decrease formula
(original value − new value) ÷ original value × 100Use this for a fall in price, marks, quantity, or measurement. A drop from 200 to 150 is a 25% decrease because 50 is one quarter of 200.
Percent of a number
percentage × value ÷ 100Use this for questions such as 12% of 450, tax on a price, a commission amount, or a discount amount before subtracting it from the original price.
Reverse percentage
final value ÷ (1 ± rate ÷ 100)Use reverse percentage when you know the final value after an increase or decrease and need the starting value before the percentage was applied.
QUICK ANSWERS
Common percentage questions
How do I find percentage increase?
Subtract the original value from the new value, divide by the original value, then multiply by 100. For example, from 80 to 100: (100 − 80) ÷ 80 × 100 = 25%.
What is the difference between percentage change and percent of a number?
Percent of a number finds a portion, such as 15% of 240. Percentage change compares two values and tells how much the second value rose or fell compared with the first value.
Why is the original value important?
Percentage increase and decrease always use the original value as the base. Using the new value as the base gives a different result and is a common mistake.
Should I use markup or profit margin?
Markup compares profit with cost. Margin compares profit with selling price. Shops often use markup for pricing and margin for reporting profitability.