Percentage Calculator Online

A percentage is a share of a number. To find a percentage of a number, multiply the number by the percentage and divide by 100. A discounted price is the price minus the discount amount.

Percentage of a number = Number × Percentage ÷ 100. Discounted price = Price − (Price × Discount ÷ 100)

For example, 15% of 2,000 UAH is 300 UAH. A product costing 2,000 UAH with a 15% discount will cost 1,700 UAH.

The calculator combines five independent calculations. Each mode has its own base and its own answer, so pick the one that matches the question rather than the one whose numbers look more familiar.

1. Find X% of Y. Enter a percentage and a number to get the amount: 15% of 2,000 UAH is 300 UAH. The percentage runs from 0 to 100 and the number up to 1,000,000,000. The result is shown with two decimal places.

Result = Number × Percentage ÷ 100

2. Price after a discount. Enter the original price and the discount to get the discounted price: 1,500 UAH − 20% = 1,200 UAH. A discount above 100% fails validation, because the price cannot go negative.

3. What percentage is X of Y. The reverse question: 50 of 200 is 25%. The second number is the base, and it cannot be zero — instead of an infinite percentage the calculator shows an error message.

4. Add or subtract a percentage. One number and one percentage, but two answers at once — "after +" and "after −". For 1,000 UAH and 15% that is 1,150 UAH and 850 UAH. This mode accepts percentages up to 10,000%: a value of 200% means adding two base amounts, so the result is three times the original.

5. Percentage change. Enter the old and the new value to get a signed change: 1,000 UAH → 1,200 UAH = +20.00%. The old value cannot be zero, because a change from a zero base is undefined and the calculator reports an error.

All five modes run in the browser; nothing is uploaded. Decimal parts can be entered with a dot or a comma.

Most practical questions run the other way: the share or the final amount is known and the original base has to be recovered. Every such case reduces to dividing by a coefficient.

The percentage and the matching amount are known. If 300 UAH is 15% of a number, that number is 300 ÷ 0.15 = 2,000 UAH. Check it the other way: 2,000 × 15% = 300 UAH.

The amount after a discount is known. A price of 1,200 UAH after a 20% discount means the original price was 1,200 ÷ 0.8 = 1,500 UAH. Adding 20% to 1,200 UAH does not work: you get 1,440 UAH, and a 20% discount on that leaves 1,152 UAH, not 1,200 UAH.

The share of a base is known. If 50 is 25% of a number, the base is 50 ÷ 0.25 = 200.

The number after a reduction is known. If 850 UAH came from subtracting 15% of the original number, the original was 850 ÷ 0.85 = 1,000 UAH.

The percentage change is known. If the new value 1,200 UAH is 20% above the old one, the old value was 1,200 ÷ 1.2 = 1,000 UAH. This is how you recover the value of a metric at the start of a period when you know how much it grew.

Original number = Known amount ÷ (1 ± Percentage ÷ 100)

The sign in the formula depends on the direction of the operation: for "number minus percentage" divide by (1 − percentage ÷ 100), for "number plus percentage" by (1 + percentage ÷ 100). With a 100% discount the denominator becomes zero and the problem simply has no solution.

A percentage is a relative value and is always compared against a base. A percentage point (pp) is the plain difference between two percentages, expressed in the same units. The two get mixed up in reporting on rates, discounts and taxes.

The key rate rose from 8% to 10%. The difference is 2 percentage points. In relative terms that is a 25% increase, because 2 ÷ 8 = 0.25. Saying "the rate rose by 2 percent" is wrong: it rose by 2 points, which is a quarter.

The reverse case sets the same trap: the rate fell from 10% to 8%. That is −2 percentage points, but only −20% relative to the previous level. Falling from 10% to 8% and rising from 8% to 10% produce the same gap in points and very different relative changes.

A discount shows two faces as well. A shop raised its discount from 15% to 20%: that is +5 percentage points, but measured against the purchase price the benefit grew by a third — 5 ÷ 15 = 33.3%. An item at 1,000 UAH used to cost 850 UAH and now costs 800 UAH, so the buyer's absolute gain is 50 UAH instead of 30 UAH.

Relative change, % = Difference in points ÷ Previous value, % × 100

The percentage calculator works with relative values: "Percentage change" shows by how much a value changed, and "What percentage is X of Y" returns the share of a base. The difference in percentage points has to be worked out by hand, subtracting one percentage from another — there is no separate mode for it.

Adding percentages taken from different bases. A 20% discount and a "−5%" delivery fee do not make −25%: 1,000 UAH → 800 UAH → 760 UAH, a total discount of 24%. Percentages add up only when the base is the same.

Confusing a percentage of a percentage. A 20% discount on an item that is already 50% off gives a 40% discount off the original price, not 70%: 1,000 → 500 → 400.

Swapping the base in a percentage change. Growth from 1,000 UAH to 1,200 UAH is +20%. Asked as a percentage of 1,200 UAH instead, the same movement is −16.67% (−200 ÷ 1,200). That is exactly the difference between "Percentage change", where the base is the old value, and "Find X% of Y", where you set the base.

Dividing by zero. "What percentage is X of Y" and "Percentage change" report an error when the base is zero. That is not a defect but a rule: a share of zero is undefined.

Rounding intermediate values. Work from exact figures: one third is not 33%. The calculator rounds its answer to two decimals, but that cannot repair an error in the base.

Related jobs have their own tools. A simple discount is handled by the "Price after a discount" mode, but finding the price before a discount, turning a fixed amount into a percentage or applying two discounts in a row belongs to the discount calculator. It also converts a fixed amount into a percentage: in the "Discount size in %" mode you enter both prices and get the percentage benefit. The link between price, profit and margin is handled by the markup and margin calculator: markup is taken from the cost price while margin is taken from the selling price, so neither can be compared directly with a discount percentage. Tax is added with the VAT calculator, and the growth of a sum over time with the compound interest calculator, where the percentage applies to the remaining balance rather than to the original amount.