16 free calculators

Math

Clear tools for percentages, discounts and practical number problems.

Tools in this category

Calculate a percentage of any number instantly.

Find the final price and savings after a discount.

Increase a value by a chosen percentage and see the exact change.

Reduce a value by a percentage and calculate the amount removed.

Find the arithmetic mean of up to four numbers.

Simplify a two-number ratio to its lowest whole-number terms.

Add two fractions and simplify the result automatically.

Find the middle value of a set of up to six numbers.

Identify the most frequent value or values in a six-number data set.

Calculate population and sample standard deviation for six values.

Compare two values using their absolute difference and average.

Calculate a circle’s area and circumference from its radius.

Calculate the area and perimeter of a rectangle.

Calculate a triangle’s area from its base and perpendicular height.

Find the hypotenuse of a right triangle from its two perpendicular sides.

Calculate a cylinder’s volume and surface area from radius and height.

Use these focused guides and worked articles to check formulas, assumptions and practical examples.