PRINCE HARRY AND MEGHAN MARKLE'S WEDDING BY THE NUMBERS:
0 - Maids of Honour - all the bridesmaids will be children.
1 - Best man - Harry's brother, the Duke of Cambridge.
1 - Hour - the length of the wedding ceremony.
2 - Rings - one for each. Not all royal grooms have chosen to wear one.
2 - Diamonds from Diana, Princess of Wales's collection used for Ms Meghan's engagement ring, plus one from Botswana.
3 - Diana's siblings at the service.
4 - The number of pageboys at the service, including Prince George. There will also be six bridesmaids, including Princess Charlotte.
6 - Harry's position in line to the throne.
6 - Windsor Grey horses taking part in the carriage ride.
7 - Charities Harry and Meghan picked to receive public donations instead of wedding gifts.
16 - The wedding will be the 16th royal wedding or blessing to take place in St George's Chapel since 1863.
20 - The temperature in degrees celsius forecast by Meteogroup for Windsor as the ceremony begins.
33 - Harry's age.
36 - Meghan's age.
200 - Guests invited to the Frogmore House evening reception.
200 - The number of Amalfi lemons being used in the cake recipe being created by baker Claire Ptak.
600 - Congregation in St George's Chapel.
2640 - People specially invited into the grounds of the castle including: 100 schoolchildren; 200 people from charities linked to Harry and Meghan; 530 members of the Royal Households and Crown Estate; 610 Windsor Castle community members; and 1200 members of the public nominated by Lord Lieutenants.
5000 - UK and international media accredited in Windsor.
100,000 - Estimated number of visitors in Windsor on the day.
STG6.3 million ($A11.3 million) - Cost of policing the Duke and Duchess of Cambridge's wedding in 2011.
26 million - The number of people who watched Harry's brother William marry Kate Middleton on British TV on April 29, 2011.
