Propagation of Error

This calculator may be used to estimate the uncertainty in a function (or formula) that is computed from measurements that have uncertainties. The program does this by randomly simulating a "bell curve" (Normal) distribution of 100 measurements for each parameter and substituting these values into the formula. The mean and standard deviation of these computed function values are then displayed.

Number of
Formula Values
with Uncertainty
Variable Index
Variable Name

Mean Value:
Uncertainty:

Enter a function in the box below.
(use correct Javascript syntax)

Function Mean: Uncertainty:

Percent (%)


Work Log

This calculator accepts mean values and their standard deviations and and uses these to randomly generate input parameter values for a user-determined function. The returned values from the function are summed and averaged to compute the best function mean value and its standard deviation. In cases where the returned value is "NaN" (not-a-number), either the user function has been typed incorrectly or the computation is in error (square root of a negative number, dividing by zero, computing the arcsine of a number greater than one,...).