Calculators
Free calculators for loans and EMI, mortgage, GST, SIP, BMI, age, percentages, fractions, GPA, dates and more, with formulas explained.
Calorie and BMR Calculator
Estimate your basal metabolic rate with the Mifflin-St Jeor equation, daily calories for your activity level, and calorie targets for losing or gaining weight.
Open toolPregnancy Due Date Calculator
Estimate your due date from the first day of your last period (with cycle length) or conception date, see weeks pregnant today and trimester dates.
Open toolFraction Calculator
Free fraction calculator for mixed numbers and fractions. Add, subtract, multiply or divide and get the simplified fraction, mixed number, decimal and steps.
Open toolGPA Calculator
Calculate semester and cumulative GPA on a 4.0 scale with plus and minus grades, credit hours and an editable grade point scale. Free and private.
Open toolCGPA to Percentage Calculator
Convert CGPA on a 10-point scale to percentage with the common 9.5 multiplier or your own, and convert percentage back to CGPA. Free and instant.
Open toolRatio Calculator
Free ratio calculator: simplify ratios to lowest terms, scale a ratio to a known value, and solve proportions A:B = C:X with the formula shown.
Open toolQuadratic Equation Solver
Solve ax² + bx + c = 0 for real or complex roots. See the discriminant, vertex, axis of symmetry and step-by-step working. Free and runs in your browser.
Open toolPrime Number Checker
Check whether a number up to 2^53 is prime, see its smallest factor and prime factorisation, or list all primes up to 1,000,000 with a sieve.
Open toolGCD & LCM Calculator
Find the greatest common divisor (HCF) and least common multiple of 2 to 10 numbers, with prime factorisations and Euclidean algorithm steps shown.
Open toolStandard Deviation Calculator
Calculate sample and population standard deviation, variance, mean, sum and count from a list of numbers, with a step-by-step table of deviations.
Open toolPermutation & Combination Calculator
Calculate nPr and nCr exactly with big integers, with or without repetition, and see the factorial working. Handles values of n and r up to 10,000.
Open toolPythagorean Theorem Calculator
Solve any missing side of a right triangle with a² + b² = c². Also gives area, perimeter, both acute angles and a labelled diagram. Free and instant.
Open toolArea and Perimeter Calculator
Find the area and perimeter of a rectangle, square, triangle, circle, trapezoid, parallelogram or ellipse in your chosen unit, with the formula shown.
Open toolAspect Ratio Calculator
Find the simplified aspect ratio of any width and height, then scale to a new width or height while keeping proportions. Includes 16:9, 4:3 and 21:9 presets.
Open toolDownload Time Calculator
Estimate how long a download takes from file size and connection speed in Mbps or MB/s, and see how much data video streaming uses at a given bitrate.
Open toolFuel Cost Calculator
Work out trip fuel cost, litres used and cost per km from distance, efficiency (km/L, L/100km, mpg) and fuel price. Split the cost and convert units.
Open toolTime Duration Calculator
Add or subtract time durations in hh:mm:ss, sum a list of durations for timesheets, and convert between h:mm:ss and decimal hours. Free and private.
Open toolDay of the Week Calculator
Find the day of the week for any date from year 100 to 9999, plus the day of the year, ISO week number, leap year status and days left in the year.
Open toolDays Until Date Calculator
Count down the days, hours, minutes and seconds to any date, with presets like New Year and Christmas. Share the countdown with a link; nothing is stored.
Open toolPercentage Calculator
Calculate percentages instantly: what is X% of Y, X is what percent of Y, and percentage increase or decrease. Free online calculator.
Open toolAge Calculator
Calculate your exact age in years, months and days from your date of birth, plus total days lived and days until your next birthday.
Open toolBMI Calculator
Calculate your body mass index from height and weight in metric or imperial units and see which adult category it falls in.
Open toolDate Difference Calculator
Find the number of days, weeks, months and years between two dates, count business days, or add and subtract days, weeks, months or years from a date.
Open toolScientific Calculator
Free online scientific calculator with brackets, powers, roots, sin, cos, tan in degrees or radians, log, ln, factorial, pi and e. Keyboard input and history.
Open toolAverage & Grade Calculator
Find the mean, median, mode, range and standard deviation of a list of numbers, then calculate a weighted grade and the score you need on your final.
Open toolAbout these calculators
Calculators save time and prevent arithmetic mistakes. This collection covers money (loans, mortgages, investments, tax and margins), health (BMI and calorie needs), school maths (fractions, GPA, geometry, statistics) and everyday questions such as dates, tips and fuel costs.
Each page shows the formula it uses and a worked example, so you can learn the method as well as get the answer. Financial and health results are estimates for planning, not professional advice.