With thanks to P&G, who's bought you brands like Venus and Olay, girls now have a formula to showing off perfect legs this summer. Based on proportions, mathematician Lily Serna says it's all in the length or positioning of a woman’s dress, skirt or shorts.

Depending on her length of body and heel hight, you can work out the right length for a perfect dress, skirt or shorts to finish - and measuring from your heels, where your jacket should fall. It's all about visual balance!

 Here's the magical formula -

(Length of your body [in cm] + heel height [in cm]) / 1.618 = Your Number (cm)

Use your number to measure from your shoulders down which will tell you where a dress, skirt or your shorts should fall to. Then by measuring from your heels up you can see where a jacket should fall – that point is your virtual waistline.

Handy Tip: If your virtual waistline is higher than your actual waistline then you should be wearing cropped jackets or high-waisted jeans. On the other hand, if your virtual waistline is lower than your real waistline you should wear longer tops or jackets.

So ladies, dress well and show off your legs. Remember to moistures top to toe and don't step outdoors with out some sunscreen on!