formula.expert

Constants library

3 values, each with its units, its uncertainty, and where it came from.

Mathematical 3

Pi exact

π=3.141592653589793\pi = 3.141592653589793

dimensionlessThe ratio of a circle's circumference to its diameter, 3.14159265358979 — an irrational and transcendental number defined, never measured.

Tau (2π) exact

τ=6.283185307179586\tau = 6.283185307179586

dimensionlessThe ratio of a circle's circumference to its radius, τ = 2π = 6.28318530717959 — one full turn, and a proposed replacement for π.

Golden Ratio exact

φ=1.618033988749895\varphi = 1.618033988749895

dimensionlessThe golden ratio φ = (1 + √5)/2 = 1.61803398874989 — the number that satisfies φ² = φ + 1 and the limit of Fibonacci ratios.