text: Before choosing a formula it is worth knowing that in the paper on the Moody chart, Moody stated the accuracy is about ±5% for smooth pipes and ±10% for rough pipes. If more than one formula is applicable in the flow regime under consideration, the choice of formula may be influenced by one or more of the following:
  *Required accuracy
  *Speed of computation required
  *Available computational technology:
  **calculator (minimize keystrokes)
  **spreadsheet (single-cell formula)
  **programming/scripting language (subroutine).