Personal Finance

Percentage

A fraction or ratio expressed as a number out of 100, denoted by the % symbol.

Also known as: percent, %, proportion

What You Need to Know

A percentage represents a portion of a whole as parts per hundred. The word "percent" literally means "per hundred." Percentages make it easy to compare proportions and calculate portions of amounts.

Basic Conversions:

  • Decimal to Percentage: Multiply by 100 (0.25 = 25%)
  • Percentage to Decimal: Divide by 100 (50% = 0.50)
  • Fraction to Percentage: Divide and multiply by 100 (3/4 = 0.75 = 75%)

Common Financial Uses:

  • Interest rates (APR, APY)
  • Investment returns
  • Tax rates
  • Discounts and markups
  • Tip calculations
  • Savings rates

Quick Mental Math:

  • 10%: Divide by 10 ($80 × 10% = $8)
  • 20%: Double the 10% amount ($8 × 2 = $16)
  • 15%: Add 10% + 5% ($8 + $4 = $12)
  • 5%: Half of 10% ($8 ÷ 2 = $4)

Percentage Point vs. Percentage: A 2% interest rate increasing to 4% is a 2 percentage point increase, but a 100% relative increase.

Sources & References

This information is sourced from authoritative government and academic institutions:

  • consumerfinance.gov

    https://www.consumerfinance.gov/consumer-tools/educator-tools/youth-financial-education/