Math

Age Difference Calculator

Calculate the exact age difference between two people in years, months, and days from their birth dates.

Coin Flip Probability Calculator

Calculate the probability of getting a specific number of heads (or tails) in a series of coin flips.

Cross Multiplication Calculator

Solve proportions using cross multiplication. Enter three values of a/b = c/d and find the unknown fourth value instantly.

Days Between Dates

Calculate the exact number of days, weeks, and months between any two dates. Also shows business days.

Dice Roll Probability Calculator

Calculate the probability of rolling a specific sum with multiple dice. Supports any number of sides.

Fraction/Decimal/Percent Converter

Convert between fractions, decimals, and percentages instantly. Enter any one form and see all three.

Mean Calculator

Calculate the arithmetic mean (average) of any set of numbers quickly.

Number Sequence Finder

Enter a number sequence and identify the pattern — arithmetic, geometric, or quadratic — then predict the next terms.

Number to Words Converter

Convert any number to its English word representation. Useful for writing checks.

Percentage of Total Calculator

Find what percentage a part is of a whole, or calculate the part from a percentage and whole. Quick and practical.

Rounding Calculator

Round numbers to any decimal place using standard rounding, ceiling, floor, or truncation. See the result instantly.

Surface Area Calculator

Calculate the surface area of common 3D shapes — cube, sphere, cylinder, and cone. Supports unit conversion.

Time Addition/Subtraction Calculator

Add or subtract hours, minutes, and seconds. Useful for timesheets, project tracking, and cooking timers.

2D Vector Calculator

Add, subtract, and compute the dot product, cross product magnitude, and angle between two 2D vectors.

2x2 Matrix Calculator

Perform matrix operations on 2x2 matrices including addition, subtraction, multiplication, determinant, and inverse.

3x3 Matrix Calculator

Calculate the determinant, transpose, and inverse of a 3x3 matrix. Enter all nine values and get instant results.

Absolute Value Calculator

Calculate the absolute value of any number. See the distance from zero on the number line.

Average Calculator

Calculate the mean, median, and mode of a set of numbers. Enter your numbers and get instant results.

Binary / Decimal / Hex Converter

Convert numbers between binary, decimal, and hexadecimal. Enter a value in any base and instantly see all conversions.

Circle Calculator

Enter any one circle measurement — radius, diameter, circumference, or area — and calculate all the others instantly.

Complex Number Calculator

Perform operations on complex numbers: add, subtract, multiply, divide, find magnitude, and conjugate.

Decimal to Fraction Converter

Convert decimals to fractions and fractions to decimals. Automatically simplifies to lowest terms.

Elapsed Time Calculator

Calculate the time difference between two times in hours, minutes, and seconds. Works with AM/PM and 24-hour formats.

Exponent Calculator

Calculate powers and exponents. Enter a base and exponent to find the result, plus see common powers.

Factorial Calculator

Calculate factorials (n!), permutations (nPr), and combinations (nCr). Essential for probability and statistics.

Fibonacci Calculator

Find the nth Fibonacci number, generate the first n terms, and see the golden ratio approximation.

Fraction Calculator

Add, subtract, multiply, or divide fractions. Shows the result as a simplified fraction and decimal.

Geometric Series Calculator

Calculate the sum of a geometric series given the first term, common ratio, and number of terms. Also shows infinite sum when |r| < 1.

GPA Calculator

Calculate your GPA on a 4.0 scale. Enter your grades and credit hours to find your grade point average.

Hex Color Converter

Convert colors between hex, RGB, and HSL formats. See a live color preview as you type.

Interest Rate Finder

Find the implied interest rate when you know the present value, future value, and number of periods. Reverse-engineer any growth rate.

LCM & GCD Calculator

Calculate the Least Common Multiple (LCM) and Greatest Common Divisor (GCD) for two or more numbers.

Logarithm Calculator

Calculate logarithms with any base. Also shows natural log (ln), log base 10, and log base 2 for any number.

Markup & Markdown Calculator

Calculate selling price from cost and markup percentage, or find the sale price from markdown percentage. Essential for retail pricing.

Mean, Median, Mode Calculator

Enter a set of numbers to find the mean, median, and mode with explanations of which measure is most appropriate for your data.

Mixed Number / Improper Fraction Converter

Convert between mixed numbers and improper fractions. Enter 3 1/2 to get 7/2, or enter 7/2 to get 3 1/2.

Modulo Calculator

Calculate the modulo (remainder) of a division. Shows quotient, remainder, and a clock arithmetic example.

Number Base Converter

Convert numbers between any bases from 2 (binary) to 36. Supports decimal, binary, octal, hexadecimal, and more.

Numerical Integration Calculator

Approximate the area under a curve using the trapezoidal rule. Enter a function f(x), bounds, and number of intervals.

Percentage Calculator

Calculate percentages easily. Find what percent of a number is, calculate percentage increase or decrease, and more.

Percentage Change Calculator

Calculate the percentage increase or decrease between two values. See the exact change and direction.

Permutation & Combination Calculator

Calculate permutations (nPr) and combinations (nCr) with step-by-step explanations showing the factorial math.

Prime Number Checker

Check if a number is prime. If not, see its factors. Also shows nearby prime numbers.

Probability Calculator

Calculate probability, odds, and expected value from events and outcomes. Covers single event, multiple events, and complementary probability.

Proportions Solver

Solve proportions: a/b = c/d. Enter any three values and find the missing fourth. Cross-multiplication made easy.

Pythagorean Theorem Calculator

Calculate the missing side of a right triangle using the Pythagorean theorem (a² + b² = c²). Find the hypotenuse or either leg.

Quadratic Formula Calculator

Solve any quadratic equation ax² + bx + c = 0. Finds real and complex roots, vertex, and discriminant.

Ratio Calculator

Simplify ratios to lowest terms or find the missing value in a proportion. Solve a:b = c:? and more.

Real-World Combinations Calculator

Calculate the total number of possible combinations for lottery numbers, PIN codes, passwords, and more. Understand your odds.

Roman Numeral Converter

Convert between decimal numbers and Roman numerals. Supports values from 1 to 3999 in both directions.

Rule of Three Calculator

Solve proportions easily: if A gives B, then C gives what? Uses cross multiplication to find the unknown fourth value.

Scientific Notation Converter

Convert between regular numbers and scientific notation. Enter either form and get the other instantly.

Significant Figures Calculator

Count the significant figures in any number and round to a specific number of sig figs. Essential for science and engineering.

Slope Calculator

Calculate the slope, y-intercept, equation, distance, and midpoint between two points on a coordinate plane.

Square Root Calculator

Calculate the square root and cube root of any number. Also checks if it is a perfect square.

Standard Deviation Calculator

Calculate the mean, variance, and standard deviation (both population and sample) for any set of numbers.

Trigonometry Calculator

Enter an angle in degrees or radians to get all six trigonometric values: sin, cos, tan, sec, csc, and cot.

Unit Rate Calculator

Calculate the price per unit or compare two rates to find the better deal. Essential for grocery shopping and cost comparisons.

Weighted Average Calculator

Calculate the weighted average (weighted mean) of values with different weights. Useful for grades, investments, and surveys.