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Percentage Increase Calculator
Wondering how much a price, salary or stat went up in percentage terms? This free percentage increase calculator finds the percent increase between any two numbers instantly. Enter the starting value and the new value, and you will see the exact percentage increase along with the formula behind it.
How to use
- Enter the old (starting) value.
- Enter the new (final) value.
- Click Calculate to see the percentage increase.
- A negative result means the value decreased.
Worked example
Last year your favorite jeans cost $36. This year they cost $45. What is the percentage increase?
Subtract: 45 - 36 = 9. Divide by the starting value: 9 / 36 = 0.25. Multiply by 100: 0.25 x 100 = 25%. The jeans increased by 25%.
Percentage points versus percent
Suppose a tax rate rises from 20% to 25%. That is a 5 percentage point increase, because 25 - 20 = 5.
But as a percent increase it is (25 - 20) / 20 x 100 = 25%. Headlines often blur the two, so always check which one is meant before comparing numbers.
Frequently asked questions
What is the percentage increase formula?
Subtract the old value from the new value, divide by the absolute value of the old value, then multiply by 100. In symbols: (new - old) / |old| x 100. For example, from $36 to $45: (45 - 36) / 36 x 100 = 25%.
What does a negative percentage increase mean?
A negative result means the value went down, not up. For example, a result of -20% is a 20% decrease. The calculator reports the direction automatically so you can read it as an increase or a decrease.
Why do you divide by the absolute value of the old number?
Using the absolute value keeps the sign of the result meaningful when the starting value is negative. It guarantees that a move toward a larger number reads as an increase and a move toward a smaller number reads as a decrease, even with negative inputs.
What if the starting value is zero?
Then the percentage increase is undefined, because you cannot divide by zero. Going from 0 to any positive number is sometimes described as an infinite increase, which is why the calculator asks for a non-zero starting value.
What is the difference between percent increase and percentage points?
They measure different things. If a rate rises from 20% to 25%, that is a 5 percentage point rise, but a 25% increase relative to the starting 20%. Mixing them up is one of the most common percentage mistakes.
Can I use decimals or negative numbers?
Yes. The calculator accepts decimals and negative values. Just remember that with negative starting values the result describes the direction of movement, so read the increase or decrease label, not only the sign.
What is the difference between percentage increase and percentage difference?
Percentage increase is directional: it compares a new value against an old one. Percentage difference compares two values with no order, dividing by their average instead. Use increase when there is a clear before and after.