Percentage Increase from 50 to 75 (Answer + Formula)
Quick answer: Going from 50 to 75 is a 50% increase.
How to calculate percentage increase
The formula is the same regardless of the numbers:
Plug in the values:
- Difference: 75 − 50 = 25
- Divide by the original: 25 ÷ 50 = 0.5
- Convert to percent: 0.5 × 100 = 50%
The critical detail: always divide by the OLD value
The most common mistake in percentage-increase calculations is dividing by the wrong number. Always divide the difference by the original value, not the new one.
If you accidentally divide by 75 instead of 50, you get 25 ÷ 75 = 33.3%, which is wrong. That number actually answers a different question: "what percent of the new value is the change?" — which is rarely what you want.
Think of it this way: percentage increase asks "how much bigger is this than where it started?" The starting point is the baseline, so it goes in the denominator.
Worked examples
Example 1: Salary raise
You were earning $50,000 and got a raise to $75,000.
- Difference: $75,000 − $50,000 = $25,000
- $25,000 ÷ $50,000 = 0.5
- 0.5 × 100 = 50% raise
Example 2: Website traffic growth
Your blog had 50 visitors a day; now it has 75.
- 75 − 50 = 25 extra visitors per day
- 25 ÷ 50 = 0.5
- 50% traffic growth
Example 3: Stock price gain
A stock went from $50 to $75 over the year.
- $25 gain ÷ $50 starting price = 0.5
- 50% annual return (before dividends and inflation)
The reverse problem: decrease from 75 back to 50
This is where percentage math gets counter-intuitive. If 50 → 75 is a 50% increase, you might expect 75 → 50 to be a 50% decrease. It isn't.
(75 − 50) ÷ 75 × 100 = 25 ÷ 75 × 100 ≈ 33.3%
Going up from 50 to 75 takes a 50% gain. Going back down from 75 to 50 takes only a 33.3% loss. This asymmetry is why stocks that drop 50% then gain 50% are not back to where they started — they're still down 25%.
Same calculation for other "old → new" pairs
To cross-check your understanding, here are several pairs and their percentage changes:
| Old | New | Change |
|---|---|---|
| 50 | 75 | +50% |
| 100 | 150 | +50% |
| 40 | 60 | +50% |
| 50 | 100 | +100% |
| 50 | 60 | +20% |
| 50 | 55 | +10% |
Negative changes (decreases)
The same formula works for decreases — you'll just get a negative number, which you can interpret as a percentage drop:
- From 50 to 40: (40 − 50) ÷ 50 × 100 = −20% (or "20% decrease")
- From 50 to 25: (25 − 50) ÷ 50 × 100 = −50%
- From 50 to 0: (0 − 50) ÷ 50 × 100 = −100%
Note that −100% is the maximum possible decrease — you can't lose more than everything you started with.
Frequently asked questions
Does the order of values matter?
Yes. The "old" value is whichever came first chronologically (or whichever is your baseline). Reversing them gives a different — and incorrect — percentage. Always identify the starting point before plugging into the formula.
What if the old value is zero?
Percentage change is undefined when the old value is zero — you can't divide by zero, and there's no meaningful baseline to compare against. In those cases, report the raw change instead ("grew from 0 to 75 daily visitors") or use a small assumed baseline.
Is "percent change" the same as "percent difference"?
No, and confusing the two is a common reporting error. Percent change has a clear "before" and "after." Percent difference compares two unrelated values (like two products) and divides by their average, not by one of them. See our percentage difference vs. percentage change guide for the full breakdown.
How do I calculate the new value if I know the old value and the percentage increase?
Multiply the old value by (1 + percentage as decimal). For 50 with a 50% increase: 50 × (1 + 0.5) = 50 × 1.5 = 75. For a 20% increase on 50: 50 × 1.2 = 60.
Use the calculator instead
Our free percentage calculator has a dedicated "Percentage Change" mode that handles both increases and decreases — just enter the old and new values and the sign is automatic. For financial scenarios specifically, the compound interest calculator shows you the full year-by-year picture of cumulative percentage growth.