11 calculators
Free basic online calculator for everyday arithmetic: addition, subtraction, multiplication, and division. Simple, clean interface for quick calculations.
Free online scientific calculator with trigonometric, logarithmic, exponential, and statistical functions. Perfect for students, engineers, and professionals.
Free percentage calculator: calculate what percent one number is of another, find percentage increases and decreases, and solve percent problems. Fast and accurate.
Free Roman numeral converter for numbers 1-3999: instantly converts any number to standard Roman numerals with a numeral chart and date examples like MMXXIV.
Free z-score calculator: enter a value, mean and standard deviation to get the z-score and percentile rank for test scores and growth charts.
Free fraction calculator: add, subtract, multiply or divide two fractions and get the simplified result, mixed number, decimal and percentage in seconds.
Free probability calculator: instantly find P(A and B), P(A or B) and conditional probabilities for independent or dependent events with clear results.
Free triangle calculator: enter three sides to instantly find the area, perimeter and all angles, and classify right, isosceles or equilateral shapes.
Free standard deviation calculator: enter numbers to get standard deviation, variance, mean and sum for a population or sample, with the exact formula.
Free confidence interval calculator: enter the sample mean, standard deviation and size to get the margin of error and 90%, 95% or 99% interval instantly.
Free volume calculator for cubes, boxes, cylinders, spheres and cones. Get instant results in cm³, liters, gallons, cubic feet and cubic inches. Select a shape.