Math

Calculator (Free, No Sign-up) — Type Full Formulas with Parentheses

A free online calculator, no sign-up needed. Type the whole formula instead of pressing buttons one at a time — supports + − * / and parentheses for complex expressions, with step-by-step results as you chain calculation...

Consumption Tax Calculator

Calculate tax-inclusive/exclusive prices and tax amount by entering a price and tax rate (10% or 8%). Supports both tax-exclusive → inclusive and inclusive → exclusive conversions.

Discount Calculator — % Off, Markdown & Half-Price in One Click

Enter the price and discount rate (%) to get the discount amount, final price, and rounding — free, no sign-up. Also explains why stacked discounts multiply, not add.

BMI Calculator

Calculate BMI (Body Mass Index) by entering your height and weight. Displays obesity classification, standard weight, and normal weight range.

Compound Interest Calculator with Monthly Deposits

Enter your principal, annual rate, period, and monthly deposit to instantly see your final balance and total interest, with a year-by-year growth chart included.

Million/Billion/Trillion Converter — 万/億/兆 (Free)

Instantly convert big numbers between Japanese units (万, 億, 兆) and English units (million, billion, trillion), with a quick-reference table and real examples.

Big Number Calculator — Exact Arithmetic with Unlimited Digits (BigInt)

Free tool for exact arithmetic on huge integers with no rounding error. Powered by JavaScript BigInt, it correctly computes addition, subtraction, multiplication, integer division (quotient and remainder), and exponentia...

Scientific Calculator (sin, cos, tan, log, power, factorial)

A free scientific calculator supporting powers, square roots, trigonometric functions (sin/cos/tan), inverse trig, logarithms (log/ln), and factorials. Switch between degrees and radians. Type expressions directly to cal...

Fraction Calculator (Common Denominator, Simplify, Add, Subtract, Multiply, Divide)

Add, subtract, multiply, or divide two fractions and see the result as both a reduced fraction and a decimal. View the step-by-step process for finding a common denominator and simplifying.

Factorial Calculator (n!, Permutations nPr, Combinations nCr)

Precisely calculate the factorial n! of a non-negative integer n. Also supports permutations (nPr) and combinations (nCr), using BigInt for exact integer results with no digit limit. Includes a factorial reference table...

Statistics Calculator (Mean, Median, Variance, Standard Deviation, Quartiles)

Paste a list of numbers separated by commas, spaces, or line breaks to instantly get the mean, median, mode, range, variance and standard deviation (both population and sample), quartiles (Q1-Q3), a frequency table, and...

Z Score Calculator (Percentile & T-Score)

Free Z score calculator that finds the Z-score, T-score, and percentile rank from a score, mean, and standard deviation, or works backward from a target percentile.

GPA Calculator (Grade Point Average)

Calculate your GPA (Grade Point Average) for free by entering each course credit hours and letter grade. Add your cumulative GPA and credits from previous semesters to get your combined cumulative GPA.

Scale Calculator (Convert Between Actual Size and Drawing Length)

Enter any two of scale ratio (1:50, 1:100, 1:200, etc.), actual size, and drawing length, and this free scale calculator instantly finds the missing value. Useful for reading architectural drawings, maps, and checking CA...

Linear Function Grapher y = ax + b (Free Online Tool)

Free tool to plot y = ax + b instantly. Enter slope a and intercept b, calculate y for any x, and hover the graph to read exact coordinates.

Quadratic Function Grapher & Calculator — Vertex and Roots

Graph y = ax² + bx + c free by entering a, b, and c. Instantly calculate the vertex, axis of symmetry, discriminant, and real roots, then inspect coordinates on the parabola.

Cubic Function Grapher & Calculator — Inflection and Extrema

Graph y = ax³ + bx² + cx + d free by entering a through d. Instantly calculate the inflection point, local maximum, and local minimum, then inspect coordinates.

Exponential Function Graph (y = a·bˣ + c)

Enter coefficient a, base b, and shift c to graph y = a·bˣ + c. Automatically computes y-intercept, horizontal asymptote, and doubling increment.

Logarithm Graph Maker — Free Online (y = a·log_b(x) + c)

Free online tool to graph y = a·log_b(x) + c. Enter coefficient a, base b, and shift c for an instant plot. Automatically computes x-intercept and vertical asymptote. Only defined for x > 0.

Ellipse Graph (x²/a² + y²/b² = 1)

Enter semi-axes a and b to graph the ellipse x²/a² + y²/b² = 1. Automatically computes area, perimeter, eccentricity, and foci. When a = b the ellipse becomes a circle.

Hyperbola Graph (x²/a² − y²/b² = 1)

Enter a and b to graph the hyperbola x²/a² − y²/b² = 1. Automatically computes eccentricity, foci, vertices, and asymptotes.

Free Pie Chart Maker — Online Tool

Create a pie chart online for free by entering labels and values, no sign-up required. This pie chart maker supports donut mode, label format toggle, and PNG download.

Arithmetic Sequence Calculator (aₙ = a₁ + (n−1)d)

Enter the first term a₁ and common difference d to compute the nth term and partial sums of an arithmetic sequence. Includes a term table and bar chart.

Geometric Sequence Calculator (aₙ = a₁·rⁿ⁻¹)

Enter the first term a₁ and common ratio r to compute the nth term, partial sums, and infinite sum (when |r| < 1). Includes a term table and bar chart.

Fibonacci Sequence Calculator — Instant Nth Term & Golden Ratio Chart

Instantly compute any term of the Fibonacci sequence, exact up to F(100) using BigInt. See the ratio of consecutive terms converge to the golden ratio φ, explore Lucas numbers, and view a bar chart of the first N terms.

Figurate Numbers Calculator (Triangular, Square, Pentagonal, Hexagonal)

Calculate triangular, square, pentagonal, and hexagonal numbers from the 1st to the Nth term and compare them on a graph. Instantly compute the value of any nth term. Includes a reference table for terms 1-15.

Prime Number Checker – Up to 1,000 Digits, Free

Check if a number up to 1,000 digits is prime — instantly and free. See the factorization, nearest primes, trial-division steps and which test proved it.

Sieve of Eratosthenes Generator (Free) – List Primes & Find the Nth Prime

Enter an upper bound to generate a list of primes with the Sieve of Eratosthenes, visualized step by step. Also look up the Nth prime (up to the 1,000,000th) — free, browser-based, no sign-up.

Prime Factorization Calculator & Tool — Free Online Site (up to 1,000,000)

Free online prime factorization calculator and tool. Enter any integer up to 1,000,000, even a specific number like 12,825, to see the factor tree, divisor list, count, and sum, plus a 1–100 reference table.

GCD & LCM Calculator

Enter two positive integers to find their greatest common divisor (GCD) using the Euclidean algorithm, with each step of the calculation shown. The least common multiple (LCM) is calculated at the same time.

Modular Arithmetic Calculator (Mod Calculator)

A modular arithmetic calculator with 4 modes: basic mod, modular addition/subtraction/multiplication, modular exponentiation (repeated squaring), and modular inverse (extended Euclidean algorithm). Handles negative mod a...

Chinese Remainder Theorem (CRT) Calculator — Solve Simultaneous Congruences

Solve a system of simultaneous congruences x ≡ a₁ (mod n₁), x ≡ a₂ (mod n₂)... with the Chinese Remainder Theorem. Automatically checks that the moduli are pairwise coprime and returns the smallest non-negative solution...

Euler's Totient Function (φ) Calculator — Coprime Counter

Enter an integer N (1 to 1,000,000) to instantly find the number of integers from 1 to N that are coprime to N (Euler's totient function φ(N)), shown with the full prime factorization and formula, not just the answer. In...

Triangle Calculator | Solve Sides, Angles & Area Instantly (SSS/SAS/ASA)

Enter three sides, or two sides and an angle, and instantly get the remaining sides, angles, area, perimeter, circumradius, and inradius — free, with SSS, SAS, and ASA input modes. Also checks whether your triangle is va...

Area Calculator

Calculate the area of a square, rectangle, triangle, parallelogram, trapezoid, rhombus, circle, sector, or ellipse — just pick a shape and the formula does the rest.

Bearing & Distance Calculator (Latitude/Longitude)

Enter the latitude and longitude of two points to calculate the great-circle distance (via the Haversine formula) and the initial bearing (angle from true north) from the first point to the second.

Volume Calculator — Cube, Cylinder, Sphere & More

Free online volume calculator for 7 shapes: cube, rectangular prism, cylinder, sphere, cone, square pyramid, and triangular prism. Pick a shape to get the formula and result instantly, plus surface area for cylinders, sp...

Vector Calculator (Dot Product, Cross Product, Magnitude, Unit Vector, Angle)

Enter two 2D or 3D vectors to instantly calculate the dot product, cross product, magnitude (norm), unit vectors, and the angle between the two vectors — a free vector calculator.

Slope Calculator (Degrees, Percent Grade, Ratio)

Enter an angle in degrees, a percent grade, or a slope ratio (1:N) and instantly convert it to the other two formats. Free tool for roads, roofs, ramps, and railways.

Free Unit Converter (Length, Weight & Temperature)

Free unit converter. Convert length (mm, cm, m, km, in, ft, yd, mi), weight (mg, g, kg, t, oz, lb), and temperature (°C, °F, K) into every unit at once from a single input.

Free Area Unit Converter (m², Tsubo, Tatami Mats, Acres & More)

Free area unit converter. Convert m², cm², km², tsubo (坪), tatami mats (畳), ares (a), hectares (ha), acres, ft², yd², and mi² — into every unit at once from a single value, including traditional Japanese real-estate un...

Shoe Size Converter — Japan (cm), US, UK, EU

Instantly convert shoe sizes between Japan (cm), US, UK, and EU systems. Get quick answers like "what is US size 8 in EU?" plus separate men's and women's charts — ideal for shopping from overseas retailers.

Ring Size Converter — Japan, US, UK, EU

Instantly convert ring sizes between Japan (go/号), US/Canada, UK/Australia, EU/France, inner circumference (mm), and inner diameter (mm). Quickly answer "what size is a Japanese size 15 ring in the US?" — handy for over...

Clothing Size Calculator & Converter (Women's & Men's / Japan, US, UK, EU)

Free calculator to convert women's and men's clothing sizes between Japan (号/size number, S/M/L), US, UK, and EU. You can also search by measured bust, chest, waist, or hip in cm. Handy for choosing the right size on ov...

Chickens and Rabbits Problem Calculator (Head & Legs Word Problem)

Free calculator for the classic "chickens and rabbits" word problem. Enter the total number of heads and legs and instantly find how many of each animal there are, with the area-diagram method visualized.

Gacha Probability Calculator (Expected Value & Pity Simulator)

Gacha probability calculator: enter your drop rate, number of pulls, and pity counter to get exact binomial odds, expected draws, median draws, and expected cost.

Fourier Series Visualiser

A free Fourier series visualiser for square, triangle, sawtooth and half-wave rectified waves. Slide the number of terms from 1 to 50 and watch the partial sum converge, read the harmonic spectrum, and see the Gibbs over...

Fourier Series Coefficient Calculator

A free Fourier series calculator that works out the Fourier coefficients a₀, aₙ and bₙ of any function by numerical integration. Enter an expression, the period interval and the highest harmonic, and see the reconstructe...