Math & Everyday Calculators
18Quick everyday calculators: percentages, area, volume, GPA, standard deviation, quadratic equations and fractions, with the working shown.
Percentage CalculatorFree percentage calculator. Find what percentage one number is of another, work out X% of Y, and calculate the increase or decrease between two values.Tip CalculatorCalculate the tip and total bill, and split it evenly between any number of people. Choose your tip percentage and see the amount per person.Age CalculatorCalculate your exact age in years, months and days from your date of birth, plus total months, weeks, days and the countdown to your next birthday.Area CalculatorCalculate the area of any shape: square, rectangle, circle, triangle or trapezoid. Results in square metres, centimetres, feet and inches.Volume CalculatorCalculate the volume of any 3D shape: cube, rectangular box, cylinder, sphere or cone. Results in m³, cm³, litres and cubic feet.Pythagorean Theorem CalculatorCalculate the hypotenuse or missing leg of a right triangle using the Pythagorean theorem. Also shows the two acute angles.Standard Deviation CalculatorCalculate mean, sample standard deviation, population standard deviation and variance from a list of numbers. Enter comma-separated values.Quadratic Equation CalculatorSolve any quadratic equation ax² + bx + c = 0 instantly. Get the discriminant, both roots (real or complex) and the nature of the solution.Fraction SimplifierSimplify any fraction to its lowest terms using the GCD method. Get the simplified fraction, decimal equivalent and percentage.GPA CalculatorCalculate your GPA (Grade Point Average) by entering your course grades and credit hours. Supports A-F letter grades and 4.0 scale.Days Between DatesCount the days and weekdays between two dates, or how many weekdays until a date from today. Shows total days, weeks, weekdays and weekend days.Hours CalculatorCalculate the hours and minutes between a start and end time, minus breaks. Built for timesheets, with the result in hours, decimal hours and total minutes.Grade CalculatorFind out what score you need on your final exam to reach your target overall grade, based on your current grade and the exam's weight.Random Number GeneratorGenerate one or more random numbers within any range, with or without duplicates. Instant, free, no signup.Ratio CalculatorSimplify a ratio to its lowest terms, or solve a proportion (A:B = C:?) for the missing value. Instant results.Date Difference CalculatorFind the difference between two dates expressed as years, months and days - not just a raw day count. Great for anniversaries, timelines and historical dates.Business Days CalculatorFind the date N business days after or before a given date, skipping weekends. Useful for deadlines, shipping estimates and project planning.Countdown TimerFind out exactly how many days, weeks and months until (or since) any event - a wedding, deadline, launch date, holiday or anniversary.