Percentage Calculator
Solve any percentage problem in seconds — right in your browser. This free percentage calculator now covers 14 distinct calculations people actually search for: what is X% of a number, what percent one value is of another, percentage increase and decrease, discounts, tips, sales tax, markup, profit and loss, reverse percentages, percentage difference, percentage-point difference, successive (compounding) percentage changes, and splitting a total amount by percentage. Pick the calculation you need from the dropdown, enter your numbers, and get an instant, accurate answer with a plain-English explanation. It's perfect for shopping, business pricing, tax and tip math, grading, finance, and everyday quick math. Everything runs locally on your device — nothing you enter is uploaded or stored. No signup, no limits.
About Percentages
A percentage is a way of expressing a number as a fraction of 100 — the word literally means "per hundred." It shows up everywhere: discounts, taxes, tips, interest rates, grades, statistics, business margins, and salary changes. Most percentage confusion comes from mixing up which number is the "base" a percentage is measured against, or from stacking percentages incorrectly — this tool is built to make every variation instant and correct, computed entirely in your browser.
How to Calculate a Percentage
Pick the calculation you need from the dropdown. For a simple percent of a number, enter the percent and the value — 20% of 150 gives 30. For "what percent is X of Y," enter both numbers — 30 out of 150 is 20%. For percentage change, enter the original and new values. For business math, use Discount, Sales Tax, Markup, or Profit/Loss with your prices. For anything involving two percentages themselves — like comparing rates or stacking changes — use Percentage Point Difference or Successive Percentage Changes, since those follow different rules than a simple percent-of calculation. The answer appears instantly as you type, with a plain-English sentence explaining what it means.
Percentage vs. Percentage Point — Why the Difference Matters
"Percentage" and "percentage point" are not interchangeable, even though people often use them that way. If an interest rate rises from 5% to 8%, that is a 3 percentage-point increase, but a 60% relative increase (3 ÷ 5 = 60%). News headlines and financial reports frequently blur this distinction, which can make a small change sound dramatic or a large change sound small. The Percentage Point Difference mode in this calculator shows both numbers side by side, so you always know which one you're looking at.
Common Mistakes to Avoid
Confusing "percent of" with "percent change."
Solution:
"20% of 150" and "a 20% increase on 150" are different calculations. The first gives 30; the second gives 180. Make sure you're using the right mode for what you actually need.
Mixing up the two numbers in a change calculation
Solution:
Percentage change is measured from the original value, not the new one. Swapping which number is "original" flips and distorts the result. Always enter the starting value as the original.
Forgetting that percentage increase and decrease aren't symmetric
Solution:
A 50% increase followed by a 50% decrease doesn't return you to the start. Because each percentage is taken from a different base, the two don't cancel out. Use the Successive Percentage Changes mode to see the true combined effect instead of adding the two percentages together.
Adding percentages that have different bases
Solution:
You can't simply add a 10% discount and a 10% tax as 20%, because they apply to different amounts. Apply each percentage to its correct base in the right order — use Discount and Sales Tax separately rather than combining them by hand.
Treating a percentage-point change as a percentage change
Solution:
Going from 5% to 8% is a 3 percentage-point change, not a 3% change — the actual relative change is 60%. Use the Percentage Point Difference mode when comparing two percentages, since a plain percent-of calculation will give the wrong sense of scale.
Confusing markup with profit margin
Solution:
Markup is calculated on cost price (what you paid); profit margin is calculated on selling price (what the customer paid). A 50% markup and a 50% margin are not the same number. Use the Markup calculator when you're pricing from cost, and Profit/Loss when you already know both prices.
Misplacing the decimal point
Solution:
A percent is a value out of 100, so 5% is 0.05, not 0.5. Slipping a decimal is the most common percentage error. Let the calculator handle the conversion so the decimal stays correct.
Frequently Asked Questions
Multiply the number by the percentage divided by 100. For example, 20% of 150 is 150 × 0.20 = 30. Select "What is X% of Y?" in the calculator, enter the percent and the value, and the answer appears instantly.
Divide the first number by the second, then multiply by 100. For example, 30 out of 150 is (30 ÷ 150) × 100 = 20%. Select "X is what % of Y?" and enter both numbers.
Subtract the original value from the new value, divide by the original, and multiply by 100. A positive result is an increase; negative is a decrease. Use the Percentage Increase or Percentage Decrease mode and enter your original and new values.
Enter the discount percentage and the original price. The calculator shows the final price after the discount and exactly how much you save, so you don't have to work it out by hand at the register.
Enter your bill amount and the tip percentage you want to leave. The calculator returns the tip amount and the total bill including tip, so you can decide the amount before you pay.
Enter the price before tax and the tax rate. The calculator shows the tax amount and the final total, which is useful for budgeting a purchase before you reach the checkout.
Markup is a percentage added on top of your cost price to set a selling price — use the Markup calculator by entering your cost and desired markup %. Profit/loss, on the other hand, works backward from a cost price and a selling price you already have, telling you the resulting profit or loss percentage.
Reverse percentage answers: "If X% of an unknown number equals Y, what is that number?" It's useful when you know a discounted price and the discount rate, and want to find the original price, or similar situations where you know the result of a percentage but not the starting value.
Percentage change (Increase/Decrease) assumes a clear before-and-after, like an original price and a new price. Percentage Difference is symmetric — it compares two values against their shared average when there's no obvious "before" value, which is more accurate for comparing two independent measurements.
A percentage point is the simple arithmetic difference between two percentages (8% − 5% = 3 percentage points), while a percentage change describes that difference relative to the starting percentage (a 60% relative increase, in this example). Use the Percentage Point Difference mode to see both at once.
Because the second percentage is applied to a different base than the first. A 20% discount followed by another 10% discount is not a 30% discount overall — it works out to about 28%, since the second discount applies to the already-reduced price. Use the Successive Percentage Changes mode to get the exact combined effect.
Enter your total amount and the percentage you want to allocate. The calculator shows both the allocated portion and what remains — handy for budgeting, splitting expenses, or setting aside a percentage of income or revenue.
No. All calculations run locally in your browser — nothing you enter is uploaded, logged, or stored on any server. That makes the tool private and safe to use for any numbers, since your figures never leave your device.
Percentage Calculator — 14 Percentage Tools in One, Free and Instant
This percentage calculator brings together every common percentage calculation in a single tool, so you never have to hunt for a different calculator for a different question. Choose your calculation from the dropdown and the result updates as you type — no button-click delay, no page reload.
The calculations available are:
- What is X% of Y? — the classic "percent of a number" calculation, used for discounts, tips, taxes, and interest.
- X is what % of Y? — find what percentage one number represents of another, useful for scores, progress, and proportions.
- Percentage increase and Percentage decrease — the percent change between an original and a new value, for price changes, growth, and comparisons.
- Discount calculator — enter a discount % and an original price to see the final price and how much you save.
- Tip calculator — enter a bill amount and a tip %, get the tip amount and the total.
- Sales tax calculator — enter a price and a tax rate to get the tax amount and the final total.
- Markup calculator — enter a cost price and a target markup % to get the selling price.
- Profit/loss calculator — enter a cost price and a selling price to see the profit or loss percentage.
- Reverse percentage — if X% of an unknown number equals Y, this finds the unknown number.
- Percentage difference — a symmetric comparison between two values relative to their average, when there's no clear "before" and "after."
- Percentage point difference — the difference between two percentages themselves (e.g. going from 5% to 8% is a 3 percentage-point difference), shown alongside the relative percentage change so the two are never confused.
- Successive percentage changes — applies two percentage changes one after another (e.g. a discount followed by another discount, or two raises in a row) and shows the true combined effect, which is never simply the sum of the two percentages.
- Split a total by percentage — enter a total and a percentage to allocate, and see both the allocated portion and what's left over.
Every calculation happens locally in your browser. Nothing you enter is uploaded, logged, or stored on any server, so it's safe to use for personal budgets, business pricing, or any other sensitive numbers.