To help would be instructors at small clubs and FTO and maybe even some instructors that wish to enhance their earnings potential, I have produced a spreadsheet to take away the guesswork and help financial planning. Contains 25 variables all easily altered and calculations are automated.
http://www.skywalkerassociates.co.uk/FIEarnings.xls
It is not password protected so it could be developed to suit your needs. Feedback is welcomed so long as it is constructive.
Edited: Maybe this would be better on another forum but it is useful for what if scenario testing such as, what if the availablity of students wx a/c changes? or what if I extend my working hours or sickness what is the effect and can I manage even if I raised my hourly rate or retainer by £x etc. The .xls is from an Excel spreadsheet but is a common format.