Error Function Calculator
Evaluate the error function erf(x) and its complement erfc(x).
The error function appears throughout probability, statistics and diffusion problems.
The math behind it
erf(x) is the integral of a Gaussian and is computed here with the Abramowitz–Stegun rational approximation (accurate to about 7 decimal places). erfc(x) = 1 − erf(x).
Worked example
erf(1) ≈ 0.8427, so erfc(1) ≈ 0.1573.
FAQ
How does this relate to the normal distribution?
The normal CDF Φ(x) = ½(1 + erf(x/√2)).