Percentage Increase / Decrease Calculator
Enter the original and the new value — get the percent change, its direction, and the difference instantly.
How to use
- Enter the original (starting) value.
- Enter the new (ending) value.
- Read the percentage change with an increase/decrease label and the absolute difference.
Examples
Salary raise
From $3,200 to $3,500: the difference is +$300, which is a 9.375% increase.
Price drop
A jacket goes from $120 to $90: the difference is −$30, a 25% decrease.
Traffic growth
Monthly visitors grow from 8,400 to 12,600 — a 50% increase.
Month-on-month sales
Sales moved from 8,400,000 to 9,660,000 KRW. The change is 1,260,000, and against the starting figure that is a 15% increase. Reporting the percentage alongside the absolute change is what keeps it honest: 15% growth on a small base and on a large base are very different pieces of news.
Reading a discount claim
A price cut from 120,000 to 90,000 KRW is a 25% reduction. The same store raising it back from 90,000 to 120,000 is a 33% increase. Both moves are 30,000 KRW, and the percentages differ only because the starting point differs. This is why a headline percentage without its base is close to meaningless.
Comparing two growth rates
A number that goes 100 to 150 grows 50%; one that goes 1,000 to 1,200 grows 20% but adds four times as many units. Growth rates favour small bases, which is why early-stage numbers look dramatic. Look at the percentage and the absolute change side by side before drawing a conclusion.
FAQ
What is the formula for percentage change?
Percentage change = (new value − original value) ÷ original value × 100. A positive result is an increase, a negative one a decrease.
Why is a $30 drop from $120 a 25% decrease but a $30 rise from $90 a 33% increase?
Because the baseline changes. Percentage change is always measured against the original value: 30 ÷ 120 = 25%, but 30 ÷ 90 ≈ 33.3%.
Percentage change vs. percentage points — what is the difference?
Percentage change is relative: going from 10% to 15% is a 50% increase. Percentage points are absolute: the same move is +5 percentage points. Use points when comparing two percentages directly.
What if the original value is zero?
Percentage change from zero is mathematically undefined (division by zero), so the tool tells you so instead of showing a misleading number. Refer to the absolute difference instead.
Increase followed by decrease — what is the net change?
Multiply the factors rather than adding the rates. A 20% rise then a 20% fall is 1.2 × 0.8 = 0.96, a net 4% decline. Three consecutive 10% rises are 1.1³ = 1.331, a 33.1% increase rather than 30%. Compounding is why a sequence of percentages never sums the way it looks like it should.
How do I reverse a percentage change?
Divide by the factor you multiplied by. If a value grew 25% and now reads 500, the original was 500 ÷ 1.25 = 400. If it fell 25% to 300, the original was 300 ÷ 0.75 = 400. Subtracting the same percentage instead of dividing is the usual error and always lands short.
What is a percentage point?
A percentage point is the arithmetic gap between two percentages, while percentage change is the relative move between them. An interest rate going from 2% to 3% rises by 1 percentage point and by 50%. Both statements are true and describe different things, which is why news about rates usually specifies which one it means.