A Leeds biology student has completed an experiment to devise the formula for the perfect night out.
Phillippa Toon sampled the best of Britain's nightlife – all in the name of academic research.
Using her own experiences and after quizzing 2,000 revellers on what made their perfect night out (PNO), the undergraduate came up with the equation pno = (a + sp) x (n + v + t + tft) x (e).
In other words, the perfect night out = (attractiveness + spontaneity) x (number of friends + venue + timing + the fun time) x (end of the evening factor).
The calculation takes into account how attractive people feel, how far in advance they planned their night out, how many friends are there, how many venues they visit, what time they start and finish, how much fun they have and how the evening ends.
Phillippa beat hundreds of mathematicians and fellow scientists to become VK Vodka Kick's "VKendologist" and come up with the formula in a competition on social networking site Facebook.
She said: "I couldn't believe it.
"I just won the chance to have a great time."
She tackled nights out in Leeds, York, Sheffield, Manchester, Newcastle and Liverpool.
Her research found a key factor was how attractive people feel.
Ideally, they should wear new, or nearly new clothes and spend up to two hours getting ready, preferably with friends.
Most prefer a planned night out but planning too far in advance leads to high expectations, whereas a week is ideal.
Revellers should go out in an even numbered group of no more than eight.
Odd numbers can mean someone is left out and more than eight is too many to organise.
They should visit no more than five venues and queue no longer than 10 minutes as bar crawls can prevent people from relaxing, while queuing creates irritation.