Percentage Calculator

A percentage is a way to express a number as a fraction of 100. The word 'percent' literally means 'per hundred.' For example, 25% means 25 out of 100, or 25/100, which equals 0.25 as a decimal.

To find what percent one number is of another, divide the smaller number by the larger number, then multiply by 100. The formula is: (Part ÷ Whole) × 100 = Percentage. For example, to find what percent 25 is of 100: (25 ÷ 100) × 100 = 25%.

To calculate a percentage of a number, convert the percentage to a decimal by dividing by 100, then multiply by the number. For example, to find 20% of 50: (20 ÷ 100) × 50 = 0.20 × 50 = 10.

Percentage change shows the relative change between two values, while percentage points measure the absolute difference between two percentages. For example, if a rate goes from 10% to 15%, that's a 50% increase but only a 5 percentage point increase.

To calculate percentage change, use this formula: ((New Value - Old Value) ÷ Old Value) × 100. If the result is positive, it's an increase. If negative, it's a decrease. For example, if a price goes from $100 to $120: ((120 - 100) ÷ 100) × 100 = 20% increase.

Percentages are used everywhere in daily life: calculating tips at restaurants, determining discounts while shopping, figuring out tax amounts, analyzing test scores, measuring business growth, calculating interest rates, and understanding statistics in news and research.

To convert a percentage to a decimal, divide by 100 (25% = 0.25). To convert a decimal to a percentage, multiply by 100 (0.25 = 25%). To convert a percentage to a fraction, put it over 100 and simplify (25% = 25/100 = 1/4).

Percentage calculations are mathematically precise when using exact numbers. However, in real-world applications, accuracy depends on the precision of your input data and how many decimal places you use. Our calculator provides accurate results to several decimal places for practical use.

For tips: multiply the bill by the tip percentage (20% tip on $50 = $50 × 0.20 = $10). For discounts: calculate the discount amount first, then subtract from the original price (30% off $100 = $100 × 0.30 = $30 discount, so final price is $70).

Yes! Percentages can exceed 100% when comparing values where the part is larger than the original whole. For example, if sales increased from 100 units to 250 units, that's a 150% increase. This commonly occurs in growth rates and comparisons.