Math & Calculation Tools
Percentage, discount, loan, statistics, primality testing, unit conversion, and more.
From household budgeting to business estimates, the targets of calculation vary widely. This section gathers tools that act as a smart calculator for the operations most prone to mental-math errors: percentage math, stacked discounts, loan amortization, basic statistical measures, primality, and temperature/unit conversion.
Tools in this topic (18)
Percentage Calculator
Calculate percentages: X% of Y, X is what % of Y, and percentage change
Discount Calculator
Calculate discount price, savings, and percentage instantly
Electricity Cost Calculator
Calculate electricity costs from wattage, hours, and rate per kWh
Loan Calculator
Calculate monthly payments, total interest, and total cost
Tip Calculator
Calculate tips and split bills easily
Salary Calculator
Convert salary between annual, monthly, and hourly rates
Statistics Calculator
Calculate mean, median, mode, variance, and standard deviation from a list of numbers
GCD & LCM Calculator
Calculate GCD and LCM of two or more numbers
Prime Number Checker & Factorization
Check if a number is prime and show its prime factorization
Pythagorean Theorem Calculator
Solve for any side of a right triangle; includes perimeter and area
Number Base Converter
Convert numbers between binary, octal, decimal, and hexadecimal instantly
Roman Numeral Converter
Convert between Roman numerals and Arabic numbers (1-3999)
Number to Words Converter
Convert numbers to English words and Japanese kanji (including daiji for formal writing)
BMI Calculator
Calculate BMI from height and weight with category and healthy range
Area Calculator
Calculate area of rectangles, circles, triangles, trapezoids, and ellipses
Temperature Converter
Convert temperatures between Celsius, Fahrenheit, and Kelvin
Unit Converter
Convert between units of length, weight, volume, and speed
Byte Unit Converter
Convert between bytes, KB, MB, GB, TB, and PB with binary and decimal standards
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