π Approximation Day — 22 July

Why 22 July?

22/7 is a common approximation of π.

22 ÷ 7 ≈ 3.142857

Actual π ≈ 3.14159

Key Facts

• Observed: 22 July
• First celebrated: 1995
• Location: Chalmers University of Technology, Gothenburg, Sweden
• π is:
  • Irrational
  • Transcendental
  • Ratio of circumference to diameter

Prelims

22 July → 22/7 → Pi Approximation Day