Percentage Increase Calculator
This percentage increase calculator finds how much a number went up, and it handles a decrease too. Enter an old value and a new one to get the percent change, and the tool tells you whether it's an increase or a decrease. You can also take a number and raise or lower it by a percent, which is perfect for a pay rise, a price change, or a sale. Every answer comes with the steps, so the math is easy to follow.
- Increase and decrease
- Two simple modes
- Steps shown
- Live change bar
- Raise a number by %
Last updated June 16, 2026 Formula: (new − old) ÷ old × 100 Reviewed by the Calcowa math team
Enter numbers to see the answer.
(75 − 50) ÷ 50 × 100 = 50%
What is percentage increase?
Percentage increase tells you how much bigger a number got, as a percent of where it started. You work it out by taking the rise, dividing by the original value, and multiplying by 100. So if something went from 50 to 75, the rise is 25, and 25 ÷ 50 × 100 = 50%, a 50% increase. The starting number always goes on the bottom, because the increase is measured against it, and that's the part people trip on.
It's the same idea for a drop. If the new value is smaller, the formula gives a negative number, and that's your percentage decrease. One formula, both directions.
How do you calculate percentage increase?
Here's how to find the percentage increase from 50 to 75:
- 1
Find the riseSubtract the old value from the new: 75 − 50 = 25.
- 2
Divide by the old value25 ÷ 50 = 0.5.
- 3
Multiply by 1000.5 × 100 = 50, so it's a 50% increase.
How to calculate percentage decrease
Percentage decrease uses the exact same formula, (new − old) ÷ old × 100, and the answer simply comes out negative. A price that falls from 80 to 60 is (60 − 80) ÷ 80 × 100 = −25%, which you read as a 25% decrease. The "Change between two numbers" mode above spots the drop and labels it for you, so you don't have to track the minus sign yourself. It's one formula doing double duty.
How to increase or decrease a number by a percent
When you know the percent and want the new total, switch to the "Increase or decrease by %" mode. To raise 200 by 15%, multiply 200 × 15 ÷ 100 to get 30, then add it on for 230. A quick trick is to multiply by 1.15 for a 15% rise, or by 0.85 for a 15% cut. That's how you bump a price, add a tip, or apply a raise in one step.
Increase vs change vs difference
These three sound alike but answer different questions. Percentage increase and percentage change both measure movement from a starting value, so the old number is the base and order matters. The percentage difference calculator compares two numbers with no clear "before", dividing by their average instead. If you've got a clear old and new value, you want the increase or change here. For the broad picture, the percentage calculator covers every percent in one place.
Everyday percentage changes
| Situation | Result |
|---|---|
| Pay rise from $50,000 to $54,000 | 8% increase |
| Price drops from $80 to $60 | 25% decrease |
| Rent goes from $1,200 to $1,320 | 10% increase |
| Stock bought at 40, now 52 | 30% gain |
| Increase 200 by 15% | 230 |
Working it out in a spreadsheet? The Excel formula is the same: type =(new − old)/old and format the cell as a percent.
Frequently asked questions
Does a 50% increase then a 50% decrease bring you back?
No, and it's a classic trap. Raise 100 by 50% to get 150, then cut 150 by 50% and you land at 75, not 100. That's because the second percent is taken from the larger number, so the ups and downs don't cancel out.
Subtract the old value from the new value, divide by the old value, then multiply by 100. So from 50 to 75 is (75 − 50) ÷ 50 × 100 = 50%. If the answer is positive it's an increase, and if it's negative it's a decrease.
It's (new − old) ÷ old × 100. The same formula covers a decrease, you just get a negative number. Keep the original value on the bottom, because the increase is always measured against where you started.
Use the same formula: (new − old) ÷ old × 100. When the new value is smaller, the result comes out negative, and that negative percent is the decrease. A drop from 80 to 60 is (60 − 80) ÷ 80 × 100 = −25%, a 25% decrease.
Multiply the number by the percent, divide by 100, and add it on. To raise 200 by 15%, that's 200 + (200 × 15 ÷ 100) = 230. A shortcut is to multiply by 1.15. The "Increase or decrease by a percent" mode above does it instantly.
Percentage increase measures change from a starting value, so the order matters and the old value is the base. Percentage difference compares two values with no clear "before", so it divides by their average instead. They answer different questions, so pick the one that fits.
Put the old value in one cell and the new in another, then use =(new − old)/old and format the cell as a percent. For example =(B2−A2)/A2. It's the same formula this calculator uses, just typed into a spreadsheet.
Take your new salary, subtract the old one, divide by the old one, and multiply by 100. A jump from $50,000 to $54,000 is (54,000 − 50,000) ÷ 50,000 × 100 = 8%. Use the "Change between two numbers" mode and enter the old and new pay.
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Need another percent?
Switch modes above, or open the full percentage calculator.