| Heir | Birth Year | Country | % Correct |
|---|---|---|---|
| Charles, Prince of Wales | 1948 | United Kingdom (and Commonwealth Realms) | 100%
|
| Princess Elisabeth, Duchess of Brabant | 2001 | Belgium | 92%
|
| Catharina-Amalia, Princess of Orange | 2003 | Netherlands | 92%
|
| Crown Princess Victoria, Duchess of Västergötland | 1977 | Sweden | 89%
|
| Prince Frederik, Count of Monpezat | 1968 | Denmark | 87%
|
| Hereditary Grand Duke Guillaume | 1981 | Luxembourg | 82%
|
| Hereditary Prince Jacques, Marquis of Baux | 2014 | Monaco | 79%
|
| Crown Prince Haakon | 1973 | Norway | 79%
|
| Crown Prince Mohammad bin Salman Al Saud | 1985 | Saudi Arabia | 74%
|
| Hereditary Prince Alois, Count of Reitberg | 1968 | Liechtenstein | 71%
|
| Crown Prince Huseein bin Abdullah | 1994 | Jordan | 68%
|
| Prince Tupouto'a 'Ulukalala | 1985 | Tonga | 66%
|
| Crown Prince Lerotholi Seeiso | 2007 | Lesotho | 63%
|
| Crown Prince Nawaf al-Ahmad al-Jaber al-Sabah | 1937 | Kuwait | 61%
|
| Crown Prince Salman bin Hamad | 1969 | Bahrain | 58%
|
| Crown Prince Moulay Hassan | 2003 | Morocco | 55%
|
| Crown Prince Mohammed bin Zayed bin Sultan Al Nahyan | 1961 | Abu Dhabi (and the whole United Arab Emirates) | 53%
|
| Crown Prince Jigme Namgyel Wangchuck | 2016 | Bhutan | 53%
|
| Crown Prince Al-Muhtadee Billah | 1974 | Brunei | 50%
|