Everyday math
Calculate the percentage increase from an original value to a new value.
Enter your numbers to see the answer.
Percentage Increase Calculator guide
A percentage increase measures how much a value has grown relative to where it started. This calculator takes the original value and the new value, divides the new by the original, and expresses the growth above 100% as the increase. It is the tool for a price that went up, a salary raise, a rent renewal, a follower count, or any before-and-after pair where the earlier figure is the reference. The denominator is always the original value, which is why the same absolute change looks bigger when the starting point is small. If the new value is lower than the original, the result comes out negative; for that situation the percentage decrease calculator gives the answer as a positive drop. When the two values are peers with no natural “before”, use the percentage difference calculator instead.
Percentage increase (%) = (new value − original value) ÷ original value × 100.
Worked example with the defaults: original value 80, new value 100. The absolute change is 100 − 80 = 20. Divide by the original: 20 ÷ 80 = 0.25. Multiply by 100 and the increase is 25%, which the calculator displays as “25% increase from 80 to 100”. Note the asymmetry: going back from 100 to 80 is a 20% decrease, not 25%, because the denominator changes to 100.
Both fields take the same unit, whatever it is: currency, weight, count, or score. The unit cancels in the division, so the result is a pure percentage. Enter plain numbers without % signs or currency symbols. If you compare quantities in different units, convert one first; otherwise the ratio is meaningless.
The result follows directly from the numbers you entered, so its accuracy is the accuracy of those inputs. The most common source of a surprising answer is a mismatch between the question you meant to ask and the one the calculator answered, so re-read the field labels if the figure looks wrong. The formula is shown above so you can check the arithmetic yourself. On this page the figure rests entirely on original value and new value, so start there if the percentage increase calculator returns something you did not expect.
Good to know: swapping the two fields is the most common error, and it changes the answer (80 → 100 is +25%, but 100 → 80 is −20%). Percentage points and percent are different: a rate rising from 4% to 5% is a 1 percentage-point rise but a 25% increase. Do not add successive increases; two 10% rises compound to 21%, not 20%.
Results are planning estimates. Check the units, product coverage, carrier rules, or local rates before making a purchase or financial decision.
How it works
Calculate the percentage increase from an original value to a new value. This tool explains the calculation so you can adjust the assumptions to match your situation.
Worked example
With Original value = 80 · New value = 100 → 25 % increase (from 80 to 100). Change an input above and this example updates with your numbers.
Common questions
25%. Subtract 80 from 100 to get 20, divide by the original 80 to get 0.25, and multiply by 100. The reverse move, 100 down to 80, is a 20% decrease because the base changes.
Subtract the original from the new value, divide by the original, and multiply by 100. The original is always the denominator. A result above 100% means the value more than doubled.
The new value is smaller than the original. For example, 100 to 80 shows −20%. The percentage decrease calculator gives the same drop as a positive 20% if you prefer that wording.
No. A 25% increase multiplies the original by 1.25, so 80 becomes 100. Percentage points describe the gap between two rates: 4% to 5% is one point but a 25% increase.
Multiply the number by (1 + rate ÷ 100). To raise 80 by 25%, multiply 80 × 1.25 = 100. To find the rate from two values, this calculator does the reverse step.