7,000 calories, three weeks off work, 15cm of snow and no more than 10 hours of shopping. These are four of the factors that make Christmas perfect according to Oxfam Unwrapped, the charity’s gift range, which has teamed up with maths expert Chris Green today to unveil its formula for a happy Christmas.

The full mathematical formula looks like this (click to enlarge):

Rick Lay, Oxfam Unwrapped campaign manager, said: “Christmas is the busiest time for Oxfam Unwrapped. Around 80% of the money we raise is given over the festive period, so we were really keen to find out what makes people happy at this time of year; what makes a perfect Christmas.

“It’s great to see that ultimately, happiness at Christmas comes down to quite simple things, such as enjoying time off work to spend with friends and family.”

Key ‘happiness factors’ include:

• Number of calories consumed on Christmas Day (any more than 7,000 calories and you’ll be too stuffed to enjoy yourself)
• Amount of time off work (just one day off boosts happiness by 70%, with three weeks being the optimum amount)
• Centimetres of snow (15cm is ideal)
• Family arguments (more than five and happiness levels plummet)
• Number of hours spent trawling the shops for gifts (any more than 10 hours and shopping-induced stress sees happiness decline rapidly)
• Miles driven to see friends and family (0 miles is ideal, with 500 miles generating a 40% reduction in happiness levels)
• The number of gifts you receive has an impact on happiness (6 gifts gets you to optimum happiness levels), but….
• ….most crucially, how many gifts you give (even giving just one present makes a huge difference to happiness levels, increasing Christmas enjoyment by 50%).

Chris Green, the mathematician who compiled the formula for Oxfam, adds:

“We conducted research into some of the key factors that people associate with Christmas and calculated optimum scores for each factor.”

What’s your score? For any like-minded boffins out there who want to work out the formula for themselves, this is what your scores mean:

“The good news is that most factors that impact on Christmas happiness are well within our control. Also, despite a lot of people thinking that Christmas is overly materialistic these days, as the formula shows, these types of things aren’t that significant.

“Most people will score between 50 – 100%, any less than 50% and it’s a case of ‘roll on January’!”

Rick Lay adds: “With the act of giving gifts topping the happiness factors, we hope that it will make people realise that Christmas is a time they can make a real difference to the happiness of others. A gift from the Oxfam Unwrapped range will not only make friends and family smile more, it will change the lives of people living in poverty all over the world.  Surely that’s got to mean a happier Christmas all around.”