Percentage Calculator

"Percent" is a unit that expresses a ratio out of 100. The word "percent" comes from the Latin "per centum": the preposition "per" means "each" or "every", and "centum" means "hundred".

Percent is used to express a ratio out of 100. For example, 50% means 50 out of 100, and 25% means 25 out of the whole.

Percent is also used in many contexts. In finance, interest rates, discount rates, and returns are expressed as percentages; in statistics, rates of change and probabilities. In everyday life, percentages are commonly used for sale prices, achievement rates, and tax rates.

Result

0% of the whole value 0 is 0.

0 out of the whole value 0 is .

If the base value 0 changes to 0, it increases by 0%.

If the base value 0 increases by 0%, it is 0.

If the base value 0 decreases by 0%, it is 0.

About This Calculator

A percentage is a ratio expressed as a fraction of 100 — the word comes from the Latin per centum, meaning "per hundred". It is the universal language for comparing proportions, whether for discounts, interest, test scores or statistics.

Enter any two of the values to find the third: what is X% of Y, what percent X is of Y, and the percentage increase or decrease between two numbers.

A percentage is a fraction with denominator 100, so 15 % of 240 is 36 and a rise from 80 to 100 is a 25 % increase. Percentage changes are not symmetric: a 25 % rise followed by a 20 % fall returns exactly to the start, whereas a 50 % fall needs a 100 % rise to recover.

Key Formula:p% of n = n × p / 100 · Change (%) = (New − Old) / Old × 100

Frequently Asked Questions

How do I calculate a percentage increase or decrease?

Subtract the old value from the new one, divide by the old value, then multiply by 100. Going from 80 to 100 is a 25% increase, but going from 100 back to 80 is only a 20% decrease, because the base changes.

Why is a 50% discount followed by another 50% only 75% off?

Percentages compound on the reduced price, not the original. Halving a price twice leaves a quarter of the original, which is a 75% total discount, not 100%.

What is the difference between percent and percentage point?

A percent change is relative to the starting value; a percentage point is an absolute difference between two percentages. Rates rising from 4% to 5% is a 1 percentage point rise but a 25% increase.

What is the difference between percentage points and percent?

Moving from 4 % to 5 % is one percentage point but a 25 % increase in the rate. Confusing the two is one of the most common mistakes in reporting interest rates and statistics.

How do I apply a 15 % discount?

Multiply by 0.85: a 240 item drops to 204. Adding 15 % back to 204 gives 234.60 rather than 240, which shows why reversing a discount means dividing by 0.85.

Related Calculators

Sources & last update

2026-10-19