People say “percent” for three jobs that do not share a formula. Percentage change asks how far a quantity moved relative to where it started. Percentage difference asks how far two values sit apart relative to their average. Percentage points ask how far two already-percent figures sit apart on the percent scale. Mixing the names is how a 3 point rise becomes a “3% increase” in a headline, or how a round-trip price change is declared even when it is not.
This article is the comparison. It is not a second calculator. The Percentage Change Calculator computes the first job only: original value, new value, a direction word, and ((new − original) ÷ original) × 100. It does not compute percentage difference. It does not subtract two rates into points. The Percentage Calculator can run the same change formula as a third mode, but its other modes answer “what is X% of Y” and “X is what percent of Y.”
The standard percentage change is ((new − original) ÷ original) × 100. From 80 to 100 that is +25%. From 100 to 80 that is −20%. Those figures are not mirrors, because the base moved. A report that says “it went up 25% and back 25%, so we are even” has changed the question mid-sentence.
Direction on YallaSolve follows the sign of (new − original): increase, decrease, or unchanged. The percentage still uses the original as the divisor. An original of 0 cannot produce a percentage; the tool says so instead of printing Infinity. Negative originals follow the same algebra. A move from −20 to −10 is an increase of 10 on a base of −20, which is −50%. That pairing looks contradictory in prose and is why the calculator page documents negative bases instead of inventing a finance convention.
Percentage difference usually means |A − B| ÷ ((A + B) ÷ 2) × 100. The two values are treated as peers. 80 and 100 give |20| ÷ 90 × 100 ≈ 22.22% in both orders. That is a useful figure when neither value is “the original”: two lab measurements, two estimates, two sensors. It is the wrong figure when one value is the starting price, the starting count, or yesterday’s reading.
YallaSolve does not offer a percentage-difference mode. If you need that symmetric gap, compute it from the definition. Do not take the output of the Percentage Change Calculator and call it a difference. The tool’s status line names change on purpose.
A percentage point is a unit on the percent scale. If a tax rate moves from 8% to 11%, that is 3 percentage points. The percentage change of the rate is (11 − 8) ÷ 8 × 100 = 37.5%. Both statements can be true. Only one of them is “it rose 3%.” News copy that drops the word “points” is the usual source of that confusion.
Points also appear when two rates are compared without a time story: candidate A at 42% and candidate B at 39% are 3 points apart. That is not a percentage change, because neither rate is the original of the other in the change formula. None of the YallaSolve percentage tools subtract two percents into points. Type the two rates as ordinary numbers and subtract if that is the job.
Use the Percentage Change Calculator when you have an original and a new amount and you want the signed change plus a direction. Use the Percentage Calculator when the question is “what is 15% of 80” or “12 is what percent of 60.” For a listed price and a percent off, that is a discount, not a change story; see how discounts, sale prices, and original prices relate.
Do not expect any of those pages to invent a fourth formula for “percent more than” wording, compound growth, or inflation. They do ordinary arithmetic on the numbers you type. If a source does not say which base it used, the figure is not finished, no matter how many decimals it shows.
Pick the formula that matches the sentence you intend to stand behind. Change names an original. Difference treats two values as equals. Points subtract two percents. Reporting the wrong one is not a rounding issue. It is a different claim.
When you write the number down, write the base too: “25% above 80,” “22% apart relative to their average,” or “3 points on the rate.” Readers can check those sentences. They cannot check “it changed 25%” once the original has left the paragraph.
The base changed. Change always divides by the original value, so the two directions are not mirrors.
No. The Percentage Change Calculator uses ((new − original) ÷ original) × 100. It does not divide by the average of the two values.
It is 3 percentage points. The percentage change of the rate is (11 − 8) ÷ 8 × 100 = 37.5%.
Percentage change is undefined. The Percentage Change Calculator reports that instead of Infinity.
