Find
Calculate what percentage one number is of another
Increase
Calculate the new value after increasing a number by a percentage
Decrease
Calculate the new value after decreasing a number by a percentage
Difference
Calculate the percentage change between two values
Percentage Difference Calculator
Calculate the percentage change between two values. Find how much a value increased or decreased as a percentage.
Formula
% change = ((after − before) / |before|) × 100Result
Enter before and after values to see the percentage change.
How to calculate percentage change between two values
Enter where a number started and where it ended up. The tool gives the change in units and as a percentage.
- 01
Put the older or reference value in Before
This is the base the change is measured against: last month's revenue, the old price, the first reading. The order matters, and swapping the boxes gives a different answer.
- 02
Put the newer value in After
The tool works out (after − before) ÷ before × 100. Revenue going from ₹80,000 to ₹95,000 is a rise of ₹15,000, which is 18.75%.
- 03
Read the sign as well as the number
A positive result is an increase and shows in green; a negative one is a decrease and shows in red. The raw difference is shown next to it, so you can see both ₹15,000 and 18.75% at once.
Percentage change versus percentage difference
This calculator gives percentage change: how far a value moved, measured against where it started. Because the base is the starting value, going up and coming back down aren't the same percentage. ₹80,000 to ₹95,000 is +18.75%, while ₹95,000 to ₹80,000 is −15.79%.
Percentage difference is a separate measure, used when neither number is the "before", such as two lab readings or two shops' prices. It divides the gap by the average of the two, so the order doesn't matter. This page doesn't calculate it, but the table shows how far apart the two measures can be.
| Values | Change, first to second | Change, second to first | Symmetric difference |
|---|---|---|---|
| 40 and 50 | +25% | −20% | 22.22% |
| ₹8,500 and ₹9,200 | +8.24% | −7.61% | 7.91% |
| ₹80,000 and ₹95,000 | +18.75% | −15.79% | 17.14% |
| 10 and 100 | +900% | −90% | 163.64% |
To get the symmetric figure yourself, take the gap, divide by the average and multiply by 100. For 40 and 50: 10 ÷ 45 × 100 = 22.22%. For small gaps the three numbers are close; for big ones, like 10 and 100, they're nowhere near each other.
Percent change when the numbers are already percentages
Say a landing page converts at 3.2% and a new version converts at 4.1%. Enter 3.2 and 4.1 and the tool says +28.13%. That's the relative change. The absolute change is 0.9 percentage points. Both are correct; they answer different questions, and reports should say which one they mean.
Two other edge cases are worth knowing. If Before is 0, there's no result, because any change from zero is infinitely large as a percentage. And when Before is negative, the tool divides by its size, so a loss shrinking from −200 to −50 shows as +75%, which matches how most people read an improvement.
Comparing before and after
Month-on-month business numbers
Sales, sign-ups or ad spend: enter last month as Before and this month as After to get the growth rate you'd put in a report.
Price rises on regular bills
If an electricity bill went from ₹2,150 to ₹2,480, the tool shows a 15.35% rise. That's easier to compare across bills than the rupee amount.
Investment returns over a period
A fund worth ₹1,20,000 that's now ₹1,38,000 has gained 15%. It's the total change, not a yearly rate, so use a CAGR or SIP calculator for annualised figures.