Free Percentage Calculator

The Percentage Calculator is a free online tool that handles multiple percentage calculations including finding percentages, percentage change, and percentage of totals.

Yes, it is completely free with no registration required. All calculations happen client-side in your browser.

The Percentage Calculator supports calculating what percent A is of B, finding a percentage of a number, percentage increase/decrease, and more.

Absolutely. The Percentage Calculator processes everything client-side in your browser. No data is uploaded to or stored on any server. Your content remains private on your device at all times.

Yes, the Percentage Calculator is fully responsive and works on smartphones and tablets. You can use it on any device with a modern web browser -- no app download required.

No account or registration is needed. Simply open the Percentage Calculator in your browser and start using it immediately. There are no sign-up walls or usage restrictions.

The Percentage Calculator uses industry-standard formulas and algorithms to ensure accurate results. However, for critical financial or medical decisions, always consult a qualified professional.

Simply enter your input in the provided field, adjust any settings to your preference, and the tool will process it instantly. You can then copy the result to your clipboard or download it.

The Percentage Calculator works in all modern browsers including Chrome, Firefox, Safari, Edge, and Opera. For the best experience, use the latest version of your preferred browser.

Margin and markup both describe profit, but against different bases, which is why they never match. Margin is profit as a share of the selling price: (profit / selling price) x 100. Markup is profit as a share of the cost: (profit / cost) x 100. Take an item that costs $50 and sells for $75. The $25 profit is a 33.33% margin but a 50% markup, so quoting one when you mean the other can badly mislead your pricing. Margin can never exceed 100%, while markup has no ceiling. A common mistake is setting a 30% markup expecting a 30% margin, when it actually yields about 23%. The Margin tab in this calculator takes your cost and selling price and shows both figures side by side with the formulas, so you always know which one you are quoting.

To find what percent one number is of another, divide the part by the whole and multiply by 100: (part / whole) x 100. For example, if you scored 35 out of 40 on a test, that is (35 / 40) x 100 = 87.5%. If 18 of 60 customers responded to a survey, that is (18 / 60) x 100 = 30%. The key is identifying which number is the whole, or total, and which is the part you are measuring against it. People often flip the two or forget the final multiply by 100, leaving a decimal like 0.875 instead of a percentage. The Of Total tab handles this directly: enter the part and the whole, and it returns the percentage plus a step-by-step breakdown so you can see exactly how the answer was reached and check your own work.

This is a reverse percentage problem, and it trips many people because you cannot just add the percentage back. If a sale price of $75 represents 25% of the original, divide the known amount by its percentage as a decimal: 75 / 0.25 = $300. For tax, if a $108 total already includes 8% tax, the pre-tax price is 108 / 1.08 = $100, not $108 minus 8%. Subtracting the percentage from the final figure gives the wrong answer because the percentage was taken from the smaller original, not the larger total. The Reverse tab handles the first case, letting you enter a known result and its percentage to recover the original value, and it shows a verification check so you can confirm the figure. For tax-inclusive totals, divide by one plus the rate as a decimal.

Stacked discounts are applied one after another, not added together, so they compound on a shrinking amount. Take a $100 item with 20% off, then an extra 10% off. The first discount drops it to $80, and the second 10% comes off that $80, removing only $8 rather than $10, leaving $72. A flat 30% off would have left $70, so the stacked deal is really a 28% discount, not 30%. The math is 100 x 0.80 x 0.90 = $72. The same logic explains why two 50%-off coupons never make something free: 50% off then 50% off leaves 25% of the price. To check any real deal, use the Discount tab to apply each percentage in turn and compare the final price against what a single combined discount would cost.

Percentage change measures how much a value grew or shrank relative to its starting point. Subtract the old value from the new one, divide by the old value, then multiply by 100: ((new - old) / old) x 100. Going from 100 to 130 is ((130 - 100) / 100) x 100 = a 30% increase, while going from 130 back to 100 is about a 23% decrease, not 30%, because the base changed. The original value, not the new one, is always the denominator, which is the step people most often get wrong. A negative result means a decrease and a positive one means an increase. The Change tab does this for you: enter the original and new values, and it returns the signed percentage with a color-coded result and a step-by-step solution so the direction and size of the change are clear at a glance.