Get the classic proportions that makes women swoon.

To build the perfect body, it helps to have the right dimensions. Thankfully, the magic formula for those dimensions has been known for centuries. It’s called the golden ratio, a dividend of two measurements that’s roughly equal to 1.618. Its influence can be seen in the shape of a seashell, the spirals of a pinecone and the Parthenon in Athens. And in blueprints for the archetypal human form: Leonardo da Vinci’s Vitruvian Man and Michelangelo’s David.

In fact, whether you’re looking at art or nature, you’ll find this ideal proportion turning up everywhere. So it’s no surprise to learn that women dig a physique that measures up to the golden ratio.

An Archives of Sexual Behavior study reveals that women are most attracted to muscular men whose shoulders measure 1.6 times the size of their waists. Of course, it’s not always easy or practical to measure the width of your own shoulders; you need someone to do it for you.

But you can use your chest circumference as a handy stand-in stat.They’re just different measures of the same thing, says Dr Viren Swami, author of The Missing Arms of Venus de Milo: Reflections On the Science of Attractiveness. One of Swami’s studies shows that women prefer a chest-to-waist ratio of 1.4 instead of one in which the two measures are closer to each other. (It’s a smaller ratio than 1.6 since your chest is narrower than your shoulders.) The bottom line: when women look at men’s torsos, the V shape is victorious.

You can figure out your own proportion in three easy steps. All you need is a tape measure and a calculator.

1. Measure your shoulder circumference at its widest point; usually around your shoulders and chest in a line halfway between your nipple and collarbone. (If you’re on your own, you can measure your chest at its widest point, just below your armpits.

2. Determine your waist circumference by wrapping a measuring tape around your abdomen so that the bottom of the tape touches the top of your hip bones.3. Divide the circumference of your shoulders (or chest) by that of your waist. You don’t have to look like a cartoon superhero to hit the ideal proportion: if you use the standard from Swami’s studies, you could hit the jackpot by having a 114cm chest and an 81cm waist.

To visualise the look, think Muscle Beach 1940, not WrestleMania 2009. (For the sake of comparison, the most popular muscleman from the pre-steroid era, Steve Reeves, had a 132cm chest and a 74cm waist; a way-beyond-golden ratio of 1.8.) Leanness rules over hugeness.