What tax calculators are listed?

This index links to tools such as income tax estimators, sales tax by state, GST calculators, and payroll-related calculators.

Are these tools for the US only?

The list may include both US and general tools; check each tool for its scope.

Overview of tax and money-related calculators: income tax, sales tax, GST, payroll, and related tools.

Tax & money calculator types

What tax calculators are listed?: This index links to tools such as income tax estimators, sales tax by state, GST calculators, and payroll-related calculators.
Are these tools for the US only?: The list may include both US and general tools; check each tool for its scope.

Celsius to Fahrenheit Converter

Convert Celsius to Fahrenheit and Fahrenheit to Celsius instantly. Free temperature converter.

Tip Calculator

Calculate tip and split the bill. Enter bill amount, tip percentage, and number of people.

Roman Numeral Converter

Convert numbers to Roman numerals and Roman numerals to numbers. Supports 1–3999.

Combinations Calculator

Calculate C(n,r) — the number of ways to choose r items from n without order. Uses n!/(r!(n-r)!).

Combinations with Replacement Calculator

Calculate the number of ways to choose r items from n with repetition allowed. Formula: C(n+r-1, r).

Even Permutations Calculator

Count how many permutations of n objects are even (expressible as an even number of swaps). For n ≥ 2, equals n!/2.