Free Online Calculators
Welcome to Calculator Galore, a collection of free calculators for school, home projects, money and everyday math. Pick a calculator below, fill in the boxes and press Calculate.
Every page also explains the formula behind the answer, with a worked example you can check by hand. Nothing you type leaves your computer.
Math
- Percentage CalculatorPercent of a number, percent change, and increase or decrease by a percent.
- Proportion CalculatorSolve A/B = C/D for the missing number, with steps.
- Ratio CalculatorSimplify ratios, convert to 1:n, and split a total in a ratio.
Dates & time
- Date CalculatorDays between two dates, or add and subtract days from a date.
- Time Duration CalculatorHours and minutes between two times, overnight shifts and breaks included.
School
- GPA CalculatorSemester, weighted and cumulative GPA on the 4.0 scale.
Home & construction
- Concrete CalculatorCubic yards and bag counts for slabs, footings and columns.
- Square Footage CalculatorArea of rooms and odd-shaped spaces, plus a cost estimate.
Finance
- Amortization CalculatorMonthly payment, payoff date and full schedule, with extra payments.
- Compound Interest CalculatorSavings growth with monthly deposits and a year-by-year table.