How to use the percentage increase calculator
- 1 Enter the original value, for example last year's price.
- 2 Enter the new value, for example this year's price.
- 3 Read the percentage increase or decrease and the formula used.
- 4 To apply a change, use the lower box: choose increase or decrease, enter the number and the percent.
Avoiding common percentage change mistakes
- Divide by the old value: the change is always measured against the starting number. Going from 80 to 100 is a 25% increase, but 100 to 80 is a 20% decrease.
- Ups and downs do not cancel: a 50% rise followed by a 50% fall leaves you at 75% of where you started.
- Finding the original: if a price is 1,150 after a 15% rise, the original is 1,150 ÷ 1.15 = 1,000, not 1,150 minus 15%.
- Over 100%: doubling is a 100% increase and tripling is 200%.
- Inflation: a 10% pay rise in a year with 8% inflation is only about a 2% real rise.
Need a simple share of a number? Use the Percentage Calculator. Comparing loan rates? See what each one costs with the Loan EMI Calculator.
Features
Increase or decrease
The result shows a + or − sign and switches its label automatically.
Formula shown
See (new − old) ÷ old × 100 with your numbers in it.
Apply a percentage
Add or take off a percentage from any number in the second box.
When to use it
Prices
Fuel went from 250 to 280: that is a 12% increase. Find a share of a number with the Percentage Calculator.
Salary
Check what a 10% raise on your salary will be. See what a rate rise costs with the Loan EMI Calculator.
Business
Compare this month's sales with last month's as a percentage.
Marks and scores
See how much your test score improved between two exams.
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Frequently asked questions
How do I calculate percentage increase?
Subtract the old value from the new value, divide by the old value and multiply by 100. From 80 to 100: (100 − 80) ÷ 80 × 100 = 25%.
How do I calculate percentage decrease?
Use the same formula; the answer is negative. From 100 to 80: (80 − 100) ÷ 100 × 100 = −20%.
Why is a 25% increase not undone by a 25% decrease?
Because the base changes. 80 up 25% is 100, but 100 down 25% is 75, not 80.
What if the original value is zero?
A change from zero cannot be expressed as a percentage, because you cannot divide by zero.
How do I add a percentage to a number?
Multiply by 1 plus the percentage as a decimal. 250 plus 12% is 250 × 1.12 = 280.
How do I calculate the percentage increase in my salary?
Enter your old salary as the original value and your new salary as the new value. A rise from 60,000 to 66,000 is (66,000 − 60,000) ÷ 60,000 × 100 = 10%. To see what a planned rise will pay, use the lower box and increase your salary by the percentage you were offered.
Can the percentage increase be more than 100%?
Yes. If a value more than doubles, the increase is over 100%. Going from 50 to 150 is a 200% increase, because the rise of 100 is twice the original 50.
What is the difference between percentage change and percentage points?
If an interest rate moves from 4% to 5%, it rose by 1 percentage point, but by 25% in percentage terms. The calculator gives the percentage change.
How do I find the original value before an increase?
Divide the new value by 1 plus the percentage as a decimal. If a price is 280 after a 12% rise, the original was 280 ÷ 1.12 = 250.
How do I work out a pay rise in percent?
Subtract your old salary from the new one, divide by the old salary and multiply by 100. A rise from 80,000 to 86,000 is 6,000 ÷ 80,000 × 100 = 7.5%.
What is compound growth over several years?
Percentage changes multiply rather than add. Three years of 10% growth is 1.1 × 1.1 × 1.1 = 1.331, a 33.1% total increase, not 30%.
Built and reviewed by Hamza Farooq, founder and lead developer
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