Percentage Calculator

Percentage questions people ask

How do I calculate a percentage of a number?

Multiply the number by the percentage, then divide by 100. Example: 20% of 80 = 0.20 × 80 = 16.

How do I find what percent one number is of another?

Divide the part by the whole and multiply by 100. Example: 25 is what percent of 200? 25 ÷ 200 × 100 = 12.5%.

How do I calculate percentage increase or decrease?

Subtract the old value from the new value, divide by the absolute old value, and multiply by 100. Example: 120 to 150 is (150 − 120) ÷ 120 × 100 = +25%.

How do I add sales tax to a price?

Multiply the price by (1 + tax rate ÷ 100). Example: $50 + 8% tax = $50 × 1.08 = $54.

How do I find the original price before a discount?

Divide the sale price by (1 − discount ÷ 100). Example: $80 after 20% off → $80 ÷ 0.80 = $100.

What is the difference between percentage change and percentage difference?

Percentage change uses the original value as the base. Percentage difference uses the average of both values, so the order of the numbers doesn't matter.

How do I calculate a tip and split the bill?

Multiply the bill by the tip percent ÷ 100, add it to the bill, then divide by the number of people. Example: $64.50 with an 18% tip is $76.11 total, or $38.06 each between two people.