Calculators

Instantly compute the least common multiple (LCM) and greatest common divisor (GCD) of a list of numbers.

Compute the longer, shorter and whole segments using the golden ratio (φ ≈ 1.618) — for design and typography.

An online click counter — increment, decrement and reset. Your count is saved in your browser.

Enter options and spin the wheel to pick a random winner — perfect for decisions and giveaways.

Measure your reflexes: click when the box turns green. See your best and average reaction time in ms.

Split a list of names randomly and evenly into teams — ideal for classes, games and events.

Calculate aspect ratio and convert dimensions (16:9, 4:3...)

Generate random numbers or lists within a specified range

Convert length, weight, temperature, area, volume and speed units

Format numbers in different ways (currency, scientific, thousands separator)

Calculate bandwidth from data size and time

Convert between decimal, binary, octal, hex

Percentage calculations and change rate

Mean, median, mode, standard deviation

Fibonacci sequence and golden ratio

Check primes and factorize numbers

Solve ax²+bx+c=0 equations

Weighted average and letter grade

Calculate speed, distance and time

Greatest common divisor and least common multiple

Length, weight, volume, area, speed and more

Calculate voltage, current, resistance, power

Calculate GPA on a 4.0 scale

Calculate resistance from color bands

Calculate feels-like temperature with wind

Trigonometry, logarithms and more

Calculate area, perimeter and angles

Radius, diameter, area and circumference

Add, subtract, multiply, divide fractions

Find a side with a²+b²=c²

Arithmetic, geometric, harmonic mean

Roll virtual dice online — d4, d6, d20, d100; one-click random rolls.

Flip a virtual coin with stats

Pick random items from a list

Calculate nPr and nCr

Slope and line equation from two points

Convert numbers to scientific notation

Simplify ratios and solve proportions

Calculate modulo, remainder, quotient

Logarithm in any base (log, ln, log2)

Powers, roots, squares and cubes

Euclidean, Manhattan distance between points

Calculate n! factorial (big numbers)

Probability for independent events

Resize keeping aspect ratio

Calculate the percentage increase or decrease and absolute difference between two values.

Convert degrees, radians, gradians

Convert bits, bytes, Kb, MB, Gb