Everyone knows Santa has a busy night ahead of him. As he starts the epic journey in New Zealand, before zooming around the planet delivering presents to the millions of children, Stuff decided to have a look at just how hectic his time here will be.

Please remember we're making a lot of assumptions here, as Santa's methods really are a mystery!

HOW MANY HOUSEHOLDS WILL HE VISIT?

Warwick Smith/ Fairfax NZ Santa Claus, pictured at the Feilding Christmas Parade, will deliver almost 2 billion presents over the course of 32 hours.

Statistics New Zealand estimates there are 913,500 children aged 14 or less in New Zealand at the moment. For the sake of simplicity let's assume all have been nice this year and will be visited by Santa. Let's also assume there are about 1.9 children per family (this is based on the birthrate of 1.9 babies per woman. Yes, some houses have more than one family and some families are split, we are going to assume these two factors balance each other out), which equates to approximately 481,000 households Santa needs to visit in New Zealand to deliver presents.

HOW MUCH TIME DOES HE SPEND IN NEW ZEALAND?

As New Zealand is the first country in the world to see in Christmas Day Santa will need to start his journey around the world here if he is to maximise the time available to complete it.

AP Santa's reindeer will power his sleigh to speeds close to 800,000kmh.

READ MORE:

* Six tips to get you through your Christmas shopping

* How to survive malls at Christmas

* Mall shoppers stuck in Christmas hell

Travelling east to west with the sun, Santa will have 32 hours to complete his journey - assuming all children sleep for eight hours, he can begin delivering presents when the first of them fall asleep in New Zealand (say 9pm on Christmas Eve) and finish just before the children in his final destination - likely Ireland - begin waking at 5am on Christmas morning. Thirty-two hours is 1920 minutes, New Zealand's 913,500 children only equate to about 0.0005 per cent of the world's population aged 14 or younger of about 1.86 billion. So if Santa delivers a present to every child in the world and spreads his time evenly around all the world's children, he has about 58 seconds to deliver presents in New Zealand.

SANTA IS RATHER AWESOME EH? JUST HOW FAST IS HIS SLEIGH?

It's going to be really hard to stop at 481,000km in 58 seconds. But that's why he's Santa. But here, for the sake of argument, let's just say he employs some kind of precision-guided present cannon - a highly precise one - to make all his deliveries in the available time. Let's assume it has a range of 50km, and as New Zealand is never more than 400km wide he can cover every household by making eight north-to-south sweeps the length of the country. This means he will need to cover New Zealand's 1600km length in about 7.3 seconds per sweep. To do this he will travel at 789,041kmh on average. That's more than 100 times faster than the world's fastest manned aircraft.

WOW. HOW MANY PRESENTS DOES HE HAVE?

Let's assume Santa is feeling particularly generous this Christmas and that all 1.86 billion children in the world are going to receive a Star Wars Jedi Master Yoda for Christmas. These weigh in at 2.9kg each, meaning the total weight of Santa's sleigh when he begins his journey in New Zealand is 5.39 million tonnes. By the time he's finished delivering a Yoda to all of New Zealand's children he will only have offloaded 190,000 tonnes worth of his total haul.

TONI L SANDYS/The Washington Post New Zealand households could leave millions of cookies out for Santa and his reindeer.

HE'S GOING TO BE EXHAUSTED! AND SO WILL RUDOLPH AND CO!

Hauling this enormous sleigh of presents at speeds several hundreds of thousands times the speed of sound is going to require a lot of energy. Luckily for Santa and his reindeer people around the world will be leaving snacks out. Santa obviously won't be able to consume all these himself and as his reindeer are doing all the work he'll have to share them around. Assuming on average every New Zealand household leaves out two cookies and a glass of milk, that's about 250 calories per household - a total of 120 million calories contributed by New Zealand. The equivalent energy to about 213,000 Big Macs.