Calculators

Quick answers for everyday math.

Calculators for school, work and daily life

  • Percentages, fractions and averages.
  • Age, date differences, days from today and hours worked.
  • GPA, grades and the score you need on a final.
  • Tips, discounts and sales tax.
  • BMI and a full scientific calculator.

How the answers are worked out

Most calculators show the formula they use so you can check the working. Dates are counted in your own time zone, and the scientific calculator follows standard operator precedence: powers first, then multiplication and division, then addition and subtraction.

Calculators FAQ

Are these calculators free?

Yes. No sign-up, no watermark and no daily limit.

How do I calculate a percentage of a number?

Divide the percentage by 100 and multiply. 25% of 80 is 0.25 × 80 = 20.

How is GPA calculated?

Each grade becomes points (A = 4.0, B = 3.0 and so on), each is multiplied by the course credits, and the total is divided by the total credits.