Five percentage calculators in one — % of, what %, reverse %, % change, and % difference.
Quick answers for the combos people look up most. Click any card to see the full breakdown.
Step-by-step solutions for the most common real-world percentage problems.
You're splitting a $60 dinner check and want to leave a 15% tip. This is the "what is X% of Y" operation, applied to the bill amount.
A jacket normally costs $89 and the store is advertising "20% off." You want the final sticker price after the discount.
The sticker price is $42 and the local sales tax rate is 8.25%. You want the total you'll actually pay at the register.
You got a raise and want to know the exact percentage. This is the "percentage change" operation, going from an old value to a new one.
You answered 42 out of 60 questions correctly. You want to convert that raw score into a percentage grade.
You bought a stock at $120 and it rose to $144. You want the exact percentage gain to compare against other investments.
Quick reference for the fractions, decimals, and percentages that come up most often in everyday math. Use this chart when you need to convert between the three forms without reaching for a calculator.
| Fraction | Decimal | Percent |
|---|---|---|
| 1/2 | 0.5 | 50% |
| 1/3 | 0.333… | 33.33% |
| 2/3 | 0.667… | 66.67% |
| 1/4 | 0.25 | 25% |
| 3/4 | 0.75 | 75% |
| 1/5 | 0.2 | 20% |
| 2/5 | 0.4 | 40% |
| 3/5 | 0.6 | 60% |
| 4/5 | 0.8 | 80% |
| 1/6 | 0.167… | 16.67% |
| 1/8 | 0.125 | 12.5% |
| 3/8 | 0.375 | 37.5% |
| 5/8 | 0.625 | 62.5% |
| 7/8 | 0.875 | 87.5% |
| 1/10 | 0.1 | 10% |
| 1/20 | 0.05 | 5% |
| 1/100 | 0.01 | 1% |
Percentage Calculator Online in three simple steps — no signup, no installation required.
Scroll to the section that matches your question. The master "[%] of [number] = [result]" at the top handles any-two-fills-the-third math. Below that, three common-phrase variants ("what is X% of Y", "X is what % of Y", "X is Y% of what") mirror the exact question you'd type into Google. Further down: percentage change (from X to Y) and percentage difference (between X and Y) each have their own dedicated section.
Enter your numbers. The result updates instantly as you type — no button to press. On the Percentage Change and Percentage Difference calculators, a formula line appears below the answer so you can see exactly how the result was computed.
Every calculator on the page has its own URL anchor (#percentage-calculator-master, #what-is-x-percent-of-y, #percentage-change, #percentage-difference, and more). Copy the URL to bookmark the one you use most, or send a link to a coworker that opens straight to the right calculator.
Fast, free, and built for privacy. Here's what makes it different.
Most percentage calculators bury the mode you need or split "% increase" from "% of" across separate URLs. We stack all five — a master any-2-fills-3 equation, three common-phrase variants, percentage change, and percentage difference — on one page, each phrased as the exact question you'd type into Google. No hunting, no mode-switching.
Type a number and the answer is already there. The formula line updates with it, so you see both the result and how it was calculated in real time — no waiting, no "Calculate" button in the way.
Every calculator shows its math right in the interface — either as an inline equation ("[20] % of [150] = [30]") or, for the less obvious cases (percentage change and percentage difference), as a formula line below the result. Helpful for spreadsheet audits, homework, or client invoices where you need to show your work.
Decimals (12.5%, 49.99), negative values (−10 to 10), and numbers in the millions all work out of the box. The "% change" mode flags direction with a + or − sign and an arrow, so you see at a glance whether a number went up or down.
Tab flows naturally between inputs, auto-focus saves a click on load, and the page reflows cleanly on a phone — equations stack vertically with full-width inputs for thumb-size hit targets, then reassemble into a single inline equation on desktop. Works on every modern browser.
All calculations run in your browser — we never see your numbers, nothing is uploaded, nothing is logged. No email, no account, no "free trial that turns into a subscription". Just the tool.
Percentages show up everywhere — here are the scenarios people use this tool for most:
Figure out the final price after a store discount ("30% off $89") with the "% of" calculator, or work back from a sale price to see how big the discount really was. For one-click sale pricing, use our Discount Calculator (coming soon).
Calculate a 15%, 18%, or 22% tip on the bill with the "% of" calculator. For a one-tap tip total with bill-splitting built in, use our dedicated Tip Calculator.
Add local sales tax (GST, VAT, state tax) to a pre-tax price, or compute tax on a line-item total for an invoice. Works with any rate — even fractional ones like 8.875%. For a dedicated tool, see our Sales Tax Calculator (coming soon).
Use the "% change" calculator to see what a salary move means — 60,000 to 63,000 is a +5% raise, 60,000 to 57,000 is a 5% cut. For a workflow built around this scenario, see our Salary Raise Calculator (coming soon).
Convert a raw score into a percentage ("42 out of 60 is what %?"), or work backward from a target grade ("I need 85% — how many questions is that?"). Uses the "what percent" and "% of a number" modes.
Track percentage change in a stock price, revenue, or user count between two periods. The "% change" mode handles both increases and decreases and flags the direction with an arrow.
Everything you need to know about percentage calculator.
Use the top "Percentage Calculator" master card or the "what is X% of Y" common-phrase card. Type 20 and 150 and the result — 30 — appears instantly. The math is (percentage ÷ 100) × number.
The core formula is (part ÷ whole) × 100 = percentage. For "what is X% of Y?" rearrange to (X ÷ 100) × Y = result; for example, 20% of 150 is 0.20 × 150 = 30. For percentage change, use (new − old) ÷ |old| × 100. For percentage difference (symmetric), use |a − b| ÷ ((|a| + |b|) ÷ 2) × 100. Every calculator on this page applies one of these formulas automatically.
To convert a decimal to a percentage, multiply by 100 and add a % sign: 0.25 becomes 25%, 0.125 becomes 12.5%, 1.5 becomes 150%. To go the other way, divide the percentage by 100: 75% becomes 0.75. The calculators on this page accept either format in the number fields — type 0.2 or 20 in the percent field and you'll get different answers because they mean different things.
The top calculator has three inputs connected as "[—]% of [—] = [—]". Type values into any two and the third fills in automatically, shown in red as the computed answer. It effectively replaces three separate calculators ("what is X% of Y", "X is what % of Y", "X is Y% of what") with one compact equation. If you want the sentence form of any of these, the three common-phrase calculators below cover the same math.
Use the "X is what percent of Y" common-phrase calculator — enter the part (like 30) and the whole (like 150) and the tool returns 20%. The formula is (part ÷ whole) × 100. Handy for test scores, budget breakdowns, or figuring out what fraction of a goal you've hit.
Use the "Percentage Change Calculator" section — type the starting value in "from" and the ending value in "to". The tool returns the percentage change with a + or − sign and an up/down arrow showing direction. From 100 to 120 is +20% (↑); from 100 to 80 is −20% (↓). Direction is auto-detected, so there's no dropdown to set.
Yes — no signup, no usage cap, no paywalled "advanced" modes. Every calculator on JTooler is fully free and always will be; we run display ads outside the tool to cover hosting.
Yes. The tool runs entirely in your browser, so once the page has loaded it keeps working without an internet connection. Great for calculating tips or discounts on the go.
Yes. Every calculator on the page accepts decimals (12.5%, 49.99) and negative values, plus numbers in the millions with automatic thousands separators. The "% change" calculator uses the absolute value of the starting number so the sign stays intuitive — e.g., going from −10 to 10 is reported as +200%.
Percentage change has a direction — it's (new − old) ÷ old × 100, so it knows which value came first, and the result is signed (positive for an increase, negative for a decrease). Percentage difference is symmetric — |a − b| ÷ (average of |a| and |b|) × 100 — so swapping a and b gives the same answer, and the result is never signed. This page includes both: use change when direction matters (growth, price moves, a raise or pay cut), use difference for comparing two measurements where neither is "first."
No. Calculations happen entirely in your browser — we don't receive, log, or store any of the values you enter. Close the tab and everything is gone.
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