Percentage Calculator

Choose one of the common percentage questions at the top or select another calculation from the menu. Enter the requested values and the answer updates automatically.

The result shows the answer, a substituted calculation using your values, and supporting values such as the amount increased, amount saved, tax, profit, or per-person total where relevant.

Use Reset to return to the basic X% of Y calculation with the default example values.

To find a known percentage of a number, convert the percentage to a fraction of 100 and multiply it by the number.

For example, 20% of 250 is 20 ÷ 100 × 250, which equals 50.

This calculation is useful for commissions, completion rates, proportions, ingredients, attendance, and many other situations where a known rate is applied to a total.

Divide the part by the whole and multiply by 100. The whole is the reference value and therefore appears in the denominator.

For example, 45 correct answers out of 60 gives 45 ÷ 60 × 100 = 75%.

The result can exceed 100%. If the part is larger than the reference whole, its percentage of the whole is greater than 100%.

When the part and percentage are known but the original whole is missing, divide the part by the percentage written as a decimal.

For example, if 5 is 25% of a number, divide 5 by 0.25. The original whole is 20.

The percentage rate cannot be zero because recovering the whole would require division by zero.

Increase a number by a percentage by multiplying the starting value by 1 plus the rate divided by 100. Increasing 250 by 20% gives 250 × 1.20 = 300.

Decrease a number by a percentage by multiplying the starting value by 1 minus the rate divided by 100. Decreasing 250 by 20% gives 250 × 0.80 = 200.

These calculations answer a different question from percentage increase or percentage decrease. Increase-by and decrease-by apply a known rate; percentage increase and percentage decrease discover the rate from an original and new value.

Percentage increase measures growth relative to the original value. Moving from 80 to 100 is a 25% increase because the increase of 20 is divided by 80.

Percentage decrease measures reduction relative to the original value. Moving from 100 to 80 is a 20% decrease because the reduction of 20 is divided by 100.

The reverse calculations are not equal because they use different reference values. An increase from 80 to 100 is 25%, while a decrease from 100 to 80 is 20%.

Percentage change keeps the direction of movement. A positive result indicates growth, a negative result indicates decline, and zero indicates no change.

Use percentage change when one value is clearly the starting or original value.

Use percent difference when the two values are independent measurements and neither should be treated as the baseline.

This calculator defines percent difference as the absolute difference divided by the average of the two absolute magnitudes.

Different technical fields sometimes use another reference definition. Include the formula when reporting a percent difference in formal work.

When values are already percentages, direct subtraction produces a difference in percentage points.

A rate rising from 4% to 5% rises by 1 percentage point. Relative to the original 4%, however, the increase is 25%.

Percentage points are commonly used for rates, margins, market shares, probabilities, and similar quantities. Relative change answers a different question: how large was the movement compared with the starting value?

Discount mode applies a known discount rate and returns both the final price and the amount saved.

Markdown mode starts with an original and current price, then calculates the percentage reduction. If the current price is higher, the result is identified as a price increase instead.

Markup compares profit with cost. It is not the same as profit margin, which compares profit with selling price.

Tax adds the entered rate to a pre-tax amount. Tip adds a gratuity and can divide the total equally among a whole number of people.

Each percentage change is applied to the value produced by the previous change. The reference value therefore changes at every step.

A 10% increase followed by a 10% decrease changes 100 to 110 and then to 99. The final value is 1% below the starting value.

Likewise, 20% off followed by another 15% off produces a total discount of 32%, not 35%.

A known percentage of zero can be calculated, but a relative percentage cannot use zero as its denominator.

Percentages can be greater than 100%. Moving from 40 to 100 is a 150% increase because the increase of 60 is 1.5 times the original value.

Negative values can make percentage-change language difficult to interpret, particularly when a value crosses zero. The percentage-change and financial modes therefore use more restrictive reference values than the basic arithmetic modes.

Ten percent is one tenth, 5% is half of 10%, 25% is one quarter, and 50% is one half.

For multiplication, percentages can be exchanged: 16% of 50 equals 50% of 16. The second version may be easier to calculate mentally.

Estimate the expected size of the answer before relying on a precise displayed result.

The calculator runs entirely in your browser and does not require an account.

Entered values are not uploaded, included in the page URL, or saved by the calculator.

Financial results are arithmetic estimates. Confirm applicable taxes, fees, legal rules, contractual terms, and required rounding before using them in a real transaction.