The MilliHelen is the amount required to launch one.
Given the distinct lack of shipbuilding around the place, I think the most practical measure of feminine beauty is the microhellen - defined as the amount required to float your boat, so to speak.
That brings me to a Brain link, courtesy of the inestimable Fred Kiesche of The Eternal Golden Braid.
"Feminine beauty, the subject of philosophical and artistic musings for millennia, can be predicted by something as basic as hormones in women, but not men. Researchers at the University of St Andrews in Fife, UK, have found that womens facial attractiveness is directly related to their oestrogen levels.Plastic surgery can also help, especially for those whose puberty didn't quite go the way we would have liked it to.
Miriam Law Smith and colleagues photographed 59 women, aged between 18 and 25, every week for six weeks. On each occasion, they provided a urine sample for hormone analysis and gave information on where they were in their menstrual cycle. None of the women wore make-up, nor were they taking the contraceptive pill.
The researchers then selected the photograph of each woman that had been taken at the time of her highest urine-oestrogen level. As expected, this correlated to the point of ovulation in the womens menstrual cycles. These photographs were rated by 14 men and 15 women, also aged 18 to 25, for attractiveness, health and femininity.
The group also rated two composite face images. One composite was an amalgamation of the 10 women with the lowest peak-oestrogen levels, while the other image was a combination of the 10 women with the highest levels (see image).
Of course there may be an easier way - faking it. A further study by Law Smith's group found that when women wore make-up the correlation between perceived attraction and oestrogen levels was completely masked, because make-up improved appearance."