Percentage Calculator

Three percentage problems, three instant answers — with the math shown.

What is % of ?
is what percent of ?
From to =

The three percentage problems

Nearly every percentage question you'll ever meet is one of three shapes. "What is X% of Y?" handles tips, discounts, and tax. "X is what percent of Y?" handles test scores, progress, and "how much of my goal is done." "From X to Y" handles growth and drops — salary raises, price changes, view counts. Each row above is one shape; fill in two numbers and the answer appears with no button needed.

Mental math shortcuts worth knowing

  • 10% is easy: move the decimal one place. 10% of 340 = 34. From there, 5% is half of that, 20% is double.
  • Percentages commute: 8% of 25 equals 25% of 8 = 2. Flip whichever is easier.
  • Tips: 15% = 10% + half of 10%. On $60: 6 + 3 = $9.

Need proportional sizes instead? Try the aspect ratio calculator.

Frequently Asked Questions

How do I calculate a percentage of a number?

Multiply the number by the percentage and divide by 100. For example, 15% of 80 is 80 × 15 ÷ 100 = 12. The first calculator above does this instantly.

How do I work out what percent one number is of another?

Divide the part by the whole and multiply by 100. For example, 45 out of 60 is 45 ÷ 60 × 100 = 75%. Use the second calculator above.

How is percentage increase or decrease calculated?

Subtract the old value from the new, divide by the old value, and multiply by 100. Going from 200 to 250 is (250 − 200) ÷ 200 × 100 = a 25% increase. Negative results mean a decrease.

How do I calculate a discount price?

Use the first calculator: enter the discount percent and the original price to get the amount off, then subtract. A 30% discount on $80 is $24 off, so you pay $56.

What is a percentage point vs a percent?

If a rate moves from 10% to 12%, it rose 2 percentage points — but that is a 20% relative increase. News about interest rates and polls usually means percentage points.