The Science of Santa

Science 2014-12-19

At the most wonderful time of the year you can be bombarded with hard to answer questions from inquisitive children, like “how does Santa get round the world in one night?” These questions tend to get brushed away with the same answer…by magic.

We have done the maths and worked out the answers to some of the most awkward questions you could be asked about how Santa manages his task!

“How many stops does Santa have to make?”

Santa has a huge task ahead of him this Christmas Eve, assuming that all children get 8 hours of sleep, he has 32 hours (24+8) to deliver all the presents.

Travelling from east to west his first stop will be in the earliest time zone of Samoa and New Zealand and the last in the far west United States at Baker Island1.

Most religions and cultures have a celebration of gift giving at this time of year but Santa Claus traditionally only delivers to Christian households.

Of the 2.2 billion2 children in the world 32% identify as Christian and so Santa will have to visit approximately 640 million children3.

If there are approximately 3 children per household, spread evenly across the globe, he will have to stop at 213 million households each 2.39km apart.


“How fast would he have to travel?”

To make all the stops in 32 hours Santa will make 1849 stops per second and be travelling at an impressive 4419 km per second. That is 400 times the speed of the Voyager 1 probe and 1.47% of the speed of light.


“How heavy is his sleigh?”


Assuming every child gets an Olaf toy4 (from this year’s most popular children’s film, Frozen), the presents will weigh 217,600 metric tonnes when stationary.

That is nearly 1000 times a Boeing 747 at full capacity!

However, Einstein’s theory of relativity indicates that when relative mass increases with speed. The apparent weight of Santa’s sleigh to a stationary observer would increase to 217,623.64 metric tonnes.


“How much would Santa have to spend on presents?”


An Olaf toy4 this year is £18 new so Santa will have to spend a grand total of  £11,520,000,000. This is equivalent to the GDP of Honduras5.

So overall Santa visits millions of houses, travelling incredibly fast, pulling a very heavy sleigh and spends the equivalent of a small country on presents.


If anyone asks you how….. it’s by magic !


Tweet me your answers to difficult Christmas questions @GabyAtNotch!