Who said scienctists aren't practical, hm? Here's a formula for all our female readers.
h = Q.(12+3s /8)
h is the maximum height of the heel (in cm)
Q is a sociological factor and has a value between 0 and 1 (see below to work this out)
S is the shoe size (UK ladies sizes). This factor makes sure that the base of support is just good enough for an experienced and sober, high-heel wearer not to fall over.
p - the probability that wearing the shoes will help you 'pull' (in a range from 0 to 1, where 1 is pwhooar and 0 is stick to carpet slippers). If the shoes are a turn-off, there's no point wearing them.
y - the number of years experience you have in wearing high heels. As you become more adept, you can wear a higher heel. Beginners should take it easy.
L - the cost of the shoes, in pounds. Clearly, if the shoe is particularly expensive, you can put up with a higher heel.
t - the time since the shoe was the height of fashion, in months (0 = it's the 'in thing' right now!). One has to suffer for one's art, and if the shoes are terribly fashionable, you should be prepared to put up with a little pain.
A - units of alcohol consumed. If you're planning on drinking, be careful to give yourself a little leeway for reduced co-ordination.