Error propagation calculator

Originally from http://laffers.net/tools/error-propagation-calculator.php?scrib_clearsaved=1

Note: Be sure to precede decimal points with a zero. For example, use "0.01", never ".01".

Enter parameters
Preview your expression
Z = (X±dX) + (Y±dY)
Result
Memory

What is this good for?

Imagine you derive a new parameter (using various mathematical operations) from an existing one with a given standard deviation, and need to know what the standard deviation of that new parameter is. In other words, you want to know how the standard deviation of the primary parameter(s) propagates to the resulting parameter. This calculator simplifies the calculus by making the most common operations automatically.

Instructions

  • Enter numbers in correct format
  • "Scientific" format is acceptable (the maximum exponent = 99 as in regular calculators). Examples:
    • 0.001 can be also entered as 1e-3 or 1E-3 or 1e-03 or 1E-03 or 10e-4 and so on
    • 325 can be also entered as 3.25e2 or 3.25e+2 or 3.25e+02 and so on
  • Standard deviation by definition must be a non-negative number (i.e. it is zero or positive)
  • Enter all numbers required for given operation. Standard deviations are not required at all; if they are not entered, the calculator will perform the requested operation, but no error propagation calculation
  • Division requires a divisor other than zero
  • Logarithms require positive arguments
  • Incorrect or missing required numbers are highlighted
  • Results can be saved into memory and recalled later in the subsequent calculations. To save your result, use the "Z→M" button. To recall saved numbers (both the value and error), click "MR→X" or "MR→Y".

Further reading