The King has travelled more than 1,900 miles around the UK since he came to the throne.
Charles has spent more than a week carrying out engagements and a tour of the home nations since the death of the Queen.
Here are some of the key numbers from the past week.
– How many miles has the King travelled since the Queen’s death?
In total, Charles is estimated to have travelled more than 1,900 miles since dashing to the Queen’s bedside in Balmoral last Thursday.
Broadcaster and gardener Alan Titchmarsh, who is a friend of the King, said he had spent Wednesday working and hosting guests at Dumfries House in Cumnock, East Ayrshire.
Charles travelled 150 miles from Dumfries House to Balmoral, the Queen’s Aberdeenshire home, on Thursday.
After the Queen’s death was announced that afternoon, Charles stayed at Balmoral overnight before making the 45-mile journey to Aberdeen Airport.
Charles and Camilla, his Queen Consort, then flew 400 miles to RAF Northolt, west London, landing at around 13.34pm on Friday – his first time on English soil since becoming monarch.
Charles was given a rapturous welcome after travelling 14 miles to Buckingham Palace and stepping from his car to greet well-wishers gathered outside the gates.
Later that day, he delivered a historic televised address to the nation and had a first audience with new Prime Minister Liz Truss.
Charles spent the weekend in London, where he was formally declared head of state during a meeting of the Accession Council, had an audience with the Cabinet and shook hands with members of the public as he returned to his official London residence, Clarence House.
On Monday he made an address to Parliament before flying 400 miles to a blustery but bright Edinburgh Airport to continue his tour of the home nations.
Charles and the Queen Consort were met by Scotland’s First Minister Nicola Sturgeon and travelled 15 miles to the Palace of Holyroodhouse – where the Queen’s coffin lay at rest in the throne room.
The King led a procession behind the Queen’s coffin up the Royal Mile to St Giles’ Cathedral, joined by his siblings Anne, Andrew and Edward.
On Tuesday he left the Palace of Holyroodhouse and returned to Edinburgh Airport, where he boarded a flight travelling 140 miles to Belfast City Airport.
Continuing his Operation Spring Tide tour around the UK, Charles and Camilla were greeted by cheering crowds when they arrived at Hillsborough Castle in Co Down, the royal residence in Northern Ireland, following a 17-mile journey from the airport.
The King attended a memorial service and pledged to “seek the welfare” of all Northern Ireland’s people before flying another 320 miles back to RAF Northolt, arriving in a private plane rather than a military one.
Charles travelled 14 miles to Buckingham Palace on Tuesday evening, where he witnessed the arrival of the Queen’s coffin.
On Wednesday, the King and his sons William and Harry walked just under a mile behind the Queen’s coffin as she left Buckingham Palace for the final time ahead of her lying in state.
The King walked in line with the Princess Royal, the Duke of York and the Earl of Wessex.
Behind the quartet were the Queen’s grandsons in a line – Peter Phillips, the Duke of Sussex and the Prince of Wales.
The King had a day of quiet reflection on Thursday, September 15, at his Highgrove home in Gloucestershire, around 104 miles from his London residence.
On Friday, Charles and the Queen Consort then travelled to Wales by helicopter where they attended a service of prayer and reflection at Llandaff Cathedral.
The couple then went to the Welsh Parliament where they received condolences and met members of the Senedd.
When he returned to Buckingham Palace, a trip of about 150 miles, the King hosted faith leaders in the Bow Room before travelling to the Palace of Westminster where he mounted a vigil at the Queen’s coffin with his brothers and sister.
On Saturday, Charles met the Chiefs of Staff at Buckingham Palace before visiting police headquarters.
He also met crowds queuing to see the Queen’s coffin on the streets of central London.
– How many miles has the Queen’s coffin travelled?
By the time it arrived at Westminster Hall, the Queen’s coffin had travelled around 600 miles since leaving her beloved Balmoral for the last time on Sunday.
Thousands of people lined the streets as the cortege made its way to the nearby town of Ballater, before going to Aberdeen and Dundee.
By the time the procession reached Edinburgh’s Palace of Holyroodhouse, after more than six hours, and almost 180 miles, the crowds were 10 deep in places on the famous Royal Mile.
The Queen was then taken to St Giles’ Cathedral for a service of thanksgiving for her life before lying in state for 24 hours for the public to pay their respects.
On Tuesday the oak coffin was driven around seven miles to Edinburgh Airport before flying 400 miles to RAF Northolt.
It then travelled 14 miles to Buckingham Palace, where the Queen’s family were there to witness its arrival at the royal residence.
On Wednesday the coffin was taken from Buckingham Palace to Westminster Hall to lie in state until the morning of her funeral on September 19.
– How many people went to see the Queen lie in state at St Giles’ Cathedral?
Approximately 33,000 people filed past the Queen’s coffin at the Edinburgh cathedral.
– How many people have so far seen the Queen’s coffin in Westminster Hall?
The Department for Culture, Media and Sport does not have a current figure for how many mourners have filed past the Queen’s coffin.
The longest queuing time so far has been around 24 hours, with barriers of around 10 miles long to keep people in the line.
How many foreign dignitaries are invited to the funeral?
The event will see around 500 dignitaries from around the world descend on London for the Queen’s state funeral.
Invitations have not been sent to Russia, Belarus or Myanmar, while Iran will only be represented at an ambassadorial level, Whitehall sources have said.
How many jewels are in the Imperial State Crown placed on top of the coffin?
The crown is made of gold and set with 2,868 diamonds, 17 sapphires, 11 emeralds, 269 pearls, and four rubies.
How many people queued to see the Queen Mother lying in state?
An estimated 200,000 people turned out to pay their respects over three days to the Queen Mother in 2002 – the last person to lie in state in the UK. The funeral itself had 2,200 guests.
At their longest, queues stretched across Lambeth Bridge and all the way along the South Bank to Southwark Cathedral, with people being warned to expect a wait of up to 12 hours at peak times.
How much did the Queen Mother’s funeral cost?
The Queen Mother’s funeral arrangements cost more than £5.4 million.
Policing costs amounted to £4.3 million and the Queen Mother’s lying in state came to £825,000, according to a House of Commons research briefing paper.
How long is the royal period of mourning?
In his televised address to the nation the day after the Queen’s death, King Charles III gave the order that a period of “Royal Mourning” would be observed from then (Friday September 9) until seven days after her funeral.