You don’t need a degree in Science but it helps to know a few simple formulas and conversions. More details under each section.
Do not forget that adding seconds is a tricky business. There are some special watches, calculators or apps that add time accurately. You’ll need one because when you need to add the times in seconds for 381 scenes you’re bound to make mistakes and lose a minute on the way somewhere.
32″+45″ = 1’17 rather than 77″
a second of video is 25 frames
a second of film is 24 frames
The formula I use the most is the proportions formula. It helps me calculate feet of film stock to time.
if X feet = Y minutes then Z feet = how many minutes?
answer = Z feet x Y minutes / X feet
Reverse formula for finding out feet.
if X feet = Y minutes then how many feet = Z minutes?
answer = Z minutes x X feet / Y minutes