Math Calculators
8 free tools in this category
Percentage, averages, ratios, statistics and geometry.
Solve every common percentage problem: of, change, and what percent.
Calculate mean, median, mode, range and standard deviation of any dataset.
Add, subtract, multiply and divide fractions with simplified results.
Calculate the area and perimeter of rectangles, circles and triangles.
Work backwards from a final amount to find the original value before a percentage change.
Compare two values with relative percent difference (RPD) and percent error.
Calculate your odds of winning a Risk attack from the number of attacking and defending armies.
Work out the exact odds of a single Risk dice roll — how likely each side is to lose one or two armies with 3v2, 2v2, 3v1 and every other dice combination.