- Least Common Multiple (LCM) Calculator The least common multiple of two or more whole numbers, with the times-table and prime-factor methods.
- Binary Converter Convert binary to decimal and decimal to binary, with every step shown, for whole numbers of any size up to 256 bits.
- Circumference Calculator The circumference of a circle from its radius, diameter or area, or the diameter from the circumference, exact in terms of π.
- Decimal to Fraction Calculator Turn any decimal, including repeating decimals like 0.333…, into a fraction in simplest form and a mixed number, with the steps.
- Factorial Calculator The exact factorial (n!) of any whole number up to 1,000, with its number of digits and the steps.
- Greatest Common Factor (GCF) Calculator The greatest common factor of two or more whole numbers, with every common factor and the steps.
- Hex Converter Convert hexadecimal (hex) to decimal and binary, and back, with every step shown.
- Linear Regression Calculator The line of best fit (least-squares regression line) for your x and y data, with the slope, intercept, r and r², a scatter plot and predictions.
- Log Calculator The logarithm of any number: common log (base 10), natural log (ln) or any base, with the change-of-base formula worked out.
- Long Division Calculator Long division worked out step by step, with the remainder or the answer as a decimal.
- Margin of Error Calculator The margin of error and confidence interval for a survey or poll result, or the sample size you need for the margin you want.
- Midpoint Calculator The midpoint between two points or two numbers, or the missing endpoint from the midpoint, with the distance and the steps.
- Normal Distribution Calculator The probability below, above or between values on a normal (bell) curve from its mean and standard deviation, or the value at any percentile.
- Probability Calculator The probability of an event from its outcomes, of two independent events both or either happening, or of something happening at least once in several tries.
- Pythagorean Theorem Calculator The missing side of a right triangle from the other two, as an exact square root and a decimal, with area and angles.
- Quadratic Formula Calculator Solve ax² + bx + c = 0 with the quadratic formula: real or complex solutions, exact and decimal, with the discriminant and vertex.
- Quartile and Interquartile Range (IQR) Calculator Q1, the median, Q3 and the interquartile range of a list of numbers, with a box plot and outliers marked.
- Right Triangle Calculator Solve a right triangle from two sides, or a side and an angle: every side and angle, the area and perimeter, exact for 30-60-90 and 45-45-90 triangles.
- Roman Numeral Converter Turn numbers into Roman numerals and Roman numerals back into numbers, from 1 to 3,999, with each part explained.
- Rounding Calculator Round any number to the nearest ten, hundred, whole number, tenth or hundredth, rounding halves up, to even, or always up or down.
- Scientific Notation Calculator Convert numbers to and from scientific notation and E notation, and multiply, divide, add or subtract them.
- Significant Figures Calculator Count the significant figures in a number and round it to any number of them, with each digit explained.
- Slope Calculator The slope of a line through two points, its equation y = mx + b, and slope as a percent grade, angle and ratio.
- Square Root Calculator The square root or cube root of any number, simplified (√50 = 5√2) and as a decimal, with the steps.
- Standard Deviation Calculator Sample and population standard deviation of a list of numbers, with every step worked out.
- Variance Calculator Sample and population variance of a list of numbers, with every step worked out.
- Volume Calculator The volume of a box, cube, cylinder, sphere, cone or pyramid, in cubic units, US gallons and liters.
- Z-score Calculator Turn a score into a z-score and a percentile, look up the z table, or find the z for a percentile.
