Calculate pi
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Choose how many digits after the decimal point. Larger values take longer — results appear when the calculation finishes.

How it works

Integer scaling avoids floating-point error. Guard digits handle rounding at the boundary.

Algorithm

• Machin — fast converging identity using two arctangent terms; practical up to 100,000 digits.
• Chudnovsky — each term contributes ~14 decimal digits; the standard choice for huge digit counts.
• Nilakantha — simple series with O(1/N³) convergence; slower than Machin but easy to follow.
• Leibniz demo — alternating series; converges as O(1/N), so it is very slow to reach even a few digits.
• Monte Carlo demo — estimates π by random sampling; result varies each run and is never exact.