Basic Calculations

These tools span everyday arithmetic and the calculations you meet while studying. There is a calculator that takes an expression as you write it and a scientific calculator with sin, cos, and log, along with sales tax and discounts, fraction arithmetic with automatic reduction, statistics such as mean, median, and standard deviation, factorials with permutations and combinations, and arbitrary-precision integer arithmetic — plus BMI, compound interest, GPA, map and drawing scale, and large-number unit conversion.

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 (Add, Subtract, Multiply, Divide, Simplify)

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...

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...