Solved using a King James Bible.
“18 Here is wisdom. Let him that hath understanding count the number of the beast: for it is the number of a man; and his number is Six hundred threescore and six.” (Revelation 13:18)
Confirm the calculations here multiver.se/tools/seg/ using “George 4 William 4 Victoria 1 Edward 7 George 5 Edward 8 George 6 Elizabeth 2 William 5”
Note however: this does not necessarily mean that Prince William is this antichrist because, like popes, when the UK monarch assumes the throne, he has the option of picking whatever name he wants to use. So if Prince Charles is named the next king, which seems most likely, he nevertheless might avoid using the name “King Charles II” due to the fact that King Charles the first had his head cut off in a regicide and it would be much better to pick a different name rather than have that fact constantly reminded. So he (or Prince Harry, if he ends up the next king) could select to reign under the name “William” instead of his real name, and thus he’d still be known as “King William V” – and the total would still count to 666.
Notice – his “count” is 666, but the “number of his name” (Rev. 13:17; 15:2) is just “V” or “5” –> for more info see, Next UK King: “William V”