Calculator
Percentage Change Calculator
Find the percentage change between two values, or calculate a new value after a percent increase or decrease.
Mode A
Find % change
From value A to value B
% Change
—
Formula: ((B − A) ÷ |A|) × 100
Mode B
Find new value
After a % increase or decrease
Use negative for decrease (e.g. −15)
New value
—
Formula: A × (1 + P ÷ 100)
How it works
The percentage change formulas.
Finding % change
((100 − 80) ÷ 80) × 100 = +25% Subtract the original from the new value, divide by the absolute original, and multiply by 100. A positive result means increase; negative means decrease.
Finding new value
200 × (1 + (−15 ÷ 100)) = 170 Multiply the original by 1 plus the percentage as a decimal. For a decrease, use a negative percentage. 200 with −15% = 200 × 0.85 = 170.
Quick reference
| Original | Change | New Value | % Change |
|---|---|---|---|
| 100 | +10% | 110 | +10% |
| 100 | +25% | 125 | +25% |
| 100 | +50% | 150 | +50% |
| 100 | +100% | 200 | +100% |
| 100 | −10% | 90 | −10% |
| 100 | −25% | 75 | −25% |
| 200 | +15% | 230 | +15% |
| 80 | → 100 | 100 | +25% |
Use cases
Where percentage change shows up in real life.
Salary and raises
A salary moving from $65,000 to $71,500 is a +10% raise. Use Mode A to check an offered raise against what your employer promised, or Mode B to see what a “12% raise” actually adds to your paycheck.
Rent and housing costs
Landlords often quote increases as a flat dollar amount. A $50 increase is 5% on $1,000 rent but 6.25% on $800 rent — Mode A shows the real percentage behind the number.
Retail prices and inflation
When a grocery staple jumps from $3.20 to $3.68, that's a 15% price increase. Tracking percentage change on recurring purchases shows inflation's real impact more clearly than a single headline CPI figure.
Stock and investment returns
Percentage change is the standard way to measure investment performance. A stock moving from $40 to $52 a share is a +30% gain, letting you compare returns across stocks at very different prices.
Weight and fitness tracking
Losing 8 lbs from a 200 lb starting point is a 4% decrease — often easier to interpret against a goal like “lose 10% of body weight” than the raw number alone.
Business revenue and growth
Quarter-over-quarter revenue moving from $2.4M to $2.76M is +15% — the standard figure used in reports and investor calls. See our percentage change guide for more worked examples.
Reverse planning with Mode B
Start from one value and a target growth rate instead of two values — e.g., “If sales grow 8% next quarter from $50,000, what's the target?” Answer: $54,000.
Discounts and price drops
Mode A spots a decrease just as well as an increase: a laptop dropping from $999 to $849 is a 15.02% decrease. For “% off” style pricing specifically, the Discount Calculator is purpose-built.
Related guides
Our guide on how to calculate percentage change walks through the formula with real scenarios: rent hikes, salary raises, price drops, and investment returns — with step-by-step examples and a quick-reference cheat sheet.
For discount-specific math — finding a sale price after a "30% off" tag — use the Discount Calculator. Our guide on how to calculate percentage off covers the difference between a simple discount, stacked discounts, and reverse lookups. For general percentage math, the Percentage Calculator covers all three common cases in one place, and the Percentage of Number calculator shows what percent X is of Y with a visual bar.
FAQ
Frequently Asked Questions
Q1What is the formula for percentage change?
Percentage change = ((New Value − Original Value) ÷ |Original Value|) × 100. Subtract the original value from the new value, divide by the absolute value of the original, then multiply by 100. A positive result is a percentage increase; a negative result is a percentage decrease.
Q2What's the difference between percentage change, increase, and decrease?
Percentage change is the umbrella term for how much a value has moved, expressed as a signed percentage. Percentage increase is a positive percentage change (the new value is larger); percentage decrease is a negative percentage change (the new value is smaller). Mode A above returns the signed percentage and labels it as an increase or decrease automatically.
Q3How do I calculate a new value after a percentage increase or decrease?
Use Mode B: multiply the original value by (1 + percentage ÷ 100). For an increase, enter a positive percentage — 200 increased by 25% is 200 × 1.25 = 250. For a decrease, enter a negative percentage — 200 decreased by 15% is 200 × 0.85 = 170.
Q4Why divide by the absolute value of the original number?
Using the absolute value keeps the direction of the result consistent even when the original number is negative, as in profit/loss or temperature calculations. Without it, a negative original value could flip an actual increase into a result that looks like a decrease.
Q5Can percentage change be more than 100%?
Yes. Any time a value more than doubles, the percentage change exceeds 100%. Going from 50 to 150 is a +200% change, and going from 10 to 100 is a +900% change. There's no upper limit on percentage increase, though percentage decrease is capped at −100% (a value dropping all the way to zero).
Q6How is percentage change different from percentage points?
Percentage change measures relative change, while percentage points measure the raw arithmetic difference between two percentages. If an interest rate moves from 5% to 7%, that's a 2 percentage point increase, but a 40% percentage change ((7−5)/5 × 100). Mixing these two up is one of the most common percentage mistakes in news and finance.
Q7Does a 50% decrease followed by a 50% increase return to the original value?
No. If a value decreases 50% (200 → 100) and then increases 50% from that new, lower base (100 → 150), you end up at 150, not the original 200. Percentage changes are always calculated from the current value, so equal-but-opposite percentages don't cancel out.
Q8Is this percentage change calculator free to use?
Yes, completely free with no signup. All calculations happen instantly in your browser as you type — nothing is sent to a server, and there's no limit on how many times you can use it.
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