Percentage Increase Calculator
Apply a percent increase to any number — or find the growth rate between two values — with exact results as you type. Free, instant, precise to the decimal you choose.
Enter your values to see instant results:
Keyboard shortcuts
| Tab / Shift+Tab | Next / previous field |
| ↑ / ↓ | Step a value by 1 (Shift: 10, Alt: 0.1) |
| Enter | Copy the focused row's result |
| [ / ] | Fewer / more decimal places |
| Esc | Clear the field |
The percentage increase formula
Both directions of the problem use one relationship: new = old × (1 + p ÷ 100).
Applying an increase — you know the starting value and the percent. Multiply the value by (1 + p/100): a salary of $3,400 with a 6% raise becomes 3,400 × 1.06 = $3,604. The first row above does exactly this, and it accepts decimals (a 2.5% raise is × 1.025).
Finding the increase — you know both values and want the rate. Rearrange the
same formula: p = (new − old) ÷ old × 100. Rent going from $1,600 to $1,800 is
(1,800 − 1,600) ÷ 1,600 × 100 = 12.5%. That's the Change from… to… row, which also
handles decreases with a minus sign.
How to use it
- Enter the starting value. Type the original number into the first field — 120 in the worked example.
- Enter the percent increase. Type the growth percentage into the second field — 25 for a 25% increase.
- Read the result instantly. The new value appears as you type: 120 increased by 25% is 150. Click the result to copy it.
The mistake to avoid
Percentage increases compound; they don't add. Two 10% increases make +21%, not +20% (× 1.1 × 1.1 = 1.21), and a 50% increase is not undone by a 50% decrease — 200 grows to 300, then falls to 150. Whenever increases stack (annual raises, inflation over several years, repeated markups), multiply the factors instead of adding the percents. The same trap runs the other way in discounts — see the double-discount trap.
Percentage increase FAQ
How do I increase a number by a percentage?
Multiply the number by (1 + percent ÷ 100). To increase 120 by 25%, multiply 120 × 1.25 = 150. Doing it in one multiplication beats computing the increase separately and adding — fewer steps, fewer slips.
How do I find the percentage increase between two numbers?
Subtract the original from the new value, divide by the original, and multiply by 100: (new − old) ÷ old × 100. From 40 to 50 that's (50 − 40) ÷ 40 × 100 = 25%. That's the third row above — Change from… to… — and the percentage change calculator owns it.
What does a percentage increase over 100% mean?
The value more than doubled. A 100% increase doubles a number (200 → 400); a 150% increase means the new value is 2.5× the original (200 → 500). Growth percentages have no upper limit — only decreases are capped, at 100%.
Can I enter a negative percentage?
Yes — increasing by −10% is the same as decreasing by 10% (100 becomes 90). It's handy when a formula or spreadsheet hands you signed growth rates and you don't want to switch rows.