The latest video in the FAA’s 57 Seconds to Safer Flying series lays out 4 Rules of Thumb for Safer Takeoffs.
“Pilots should consult their performance charts prior to any takeoff, especially a takeoff that is out of the norm,” the video begins. “Knowing and applying some rules of thumb regarding takeoffs can help you make better initial decisions with go or no-go for a particular set of circumstances.”
You can read more about aircraft performance and calculations here.