Percentage Calculator
Pick what you're solving for, enter your numbers, and get the answer instantly — no signup. Also works as a percentage change calculator, percent change calculator, percentage increase calculator, percent off calculator, and percentile calculator.
Calculate a percentage
How this is calculated
X% of a number: (percent ÷ 100) × number. X is what % of Y: (X ÷ Y) × 100. Percentage change (also called percent change): ((new − old) ÷ old) × 100 — positive is an increase, so this doubles as a percentage increase calculator; negative is a decrease. Find the whole: part ÷ (percent ÷ 100). Percentile rank: (values below + half the values tied) ÷ total values × 100.
Real-world worked examples
| 18% tip on a $64.50 bill | $11.61 tip, $76.11 total |
| 30 is what % of 150 | 20% |
| Price change: $50 → $75 | +50% increase |
| Price change: $200 → $150 | -25% decrease |
| 30 is 20% of what number | 150 |
| 30% off an $85 jacket | $25.50 off, $59.50 sale price |
| Percentile of 72 in a 20-score data set | 85th percentile |
Using this as a percent off calculator
There's no separate "percent off" mode because it's the same math as "X% of a number": for 30% off an $85 jacket, use that mode to get the discount amount (30% of 85 = $25.50), then subtract it from the price yourself ($85 − $25.50 = $59.50 sale price). The "percent change" mode can also work in reverse for the same question — it'll tell you a $59.50 sale price is a 30% decrease from $85.
Percentile rank, explained
A percentile answers "how does this one value compare to the rest of the data set?" — a value at the 85th percentile scored better than (or equal to) 85% of the data set. In the worked example above, entering 20 test scores and asking for the percentile of 72 returns the 85th percentile because 17 of those 20 scores fall below 72. This is a different question from the other four modes: those compare two single numbers to each other, while percentile rank compares one number against an entire data set.
Percentage points vs. percent change
These get mixed up constantly, and the difference matters: if a survey response rate goes from 20% to 25%, that's a 5 percentage point increase (25 − 20), but it's a 25% relative increase in responses ((25−20)/20 × 100). Both numbers are correct, they're just answering different questions — "percentage change" mode above calculates the second one (relative change), not the first.
Frequently asked questions
Why is my percent change result negative?
A negative result means the new value is lower than the original — it's a decrease, not an error. Going from 200 to 150, for example, is a -25% change; the sign tells you the direction and the number tells you the magnitude.
Can I calculate a percentage change from zero?
No — percent change is undefined when the original value is 0, because you'd be dividing by zero. If your starting point is genuinely zero (going from no sales to some sales, for instance), describe it as "new" rather than as a percentage increase.
What's a quick way to calculate a tip in my head?
For 20%, move the decimal point one place left and double it (10% of $64.50 is $6.45, doubled is $12.90). For 15%, take that same 10% figure and add half of it again ($6.45 + $3.23 = $9.68). This calculator handles the exact math either way, including uneven percentages like 18% or 22%.
Can percentages go above 100%?
Yes, in the right context. "X% of a number" mode works fine above 100% (150% of 40 is 60), and percent-change or "what percent of" results exceed 100% whenever the second number is more than double the first — that's normal, not an error.
How is percentile rank different from a regular percentage?
A percentage compares two numbers directly (30 is 20% of 150). A percentile compares one value against an entire data set, answering "what share of the other values does this one beat?" — they use the word "percent" for unrelated reasons and aren't interchangeable.
Does this percentage calculator work as a percent off calculator too?
Yes, using the "X% of a number" mode: it gives you the discount amount, which you then subtract from the original price to get the sale price. See the worked example above for a full walkthrough.