What is the distance formula?

Distance = √[(x2−x1)² + (y2−y1)²]. Same as the Pythagorean theorem in 2D.

This tool is 2D only. For 3D, use √[(x2−x1)² + (y2−y1)² + (z2−z1)²].

Use any consistent units (e.g. meters, feet). The result is in the same unit.

Online Distance Between Two Points Calculator

Enter (x1, y1) and (x2, y2) to get the distance. 2D distance formula.

What is the distance formula?: Distance = √[(x2−x1)² + (y2−y1)²]. Same as the Pythagorean theorem in 2D.
Does it work in 3D?: This tool is 2D only. For 3D, use √[(x2−x1)² + (y2−y1)² + (z2−z1)²].
Units?: Use any consistent units (e.g. meters, feet). The result is in the same unit.

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.