|House Points hourglasses|
To measure how the House points
The House point hourglasses are four giant hourglasses located in the Entrance Hall used to record the number of house points that have been awarded or deducted. There is one hourglass for each of the Hogwarts Houses: Gryffindor, Hufflepuff, Ravenclaw, and Slytherin. When points are earned, some gems (depending on house colours) fall from the upper bulb into the lower. When points have been deducted, they do the opposite, retreating into the upper bulb. For example, when ten points are taken from Gryffindor, ten red gems will fall back into the upper half of the hourglass.
HistoryDuring Severus Snape's escape from Hogwarts after he killed Albus Dumbledore in 1997, a curse shattered the Gryffindor hourglass, causing red rubies to flood the floor like blood. The Slytherin hourglass was shattered in 1998 during the Battle of Hogwarts and green emeralds rolled across the floor. The two were probably repaired and remounted on the wall.
Behind the scenes
- The Gryffindor, Ravenclaw, and Slytherin hourglasses contain rubies, sapphires and emeralds, respectively. The Hufflepuff hourglasses contain a yellow gem, perhaps topaz, citrine or amber. 
- In Harry Potter and the Half-Blood Prince, when Severus Snape takes points from Harry after meeting him at the Hogwarts gates, he remarks that Gryffindor would be starting out in negative points. However, previously in Harry Potter and the Order of the Phoenix, Snape was unable to take any more points from Gryffindor when they had none left. McGonagall had to add points before any more could be removed.
- In the video game adaptations of Philosopher's Stone, Chamber of Secrets and Prisoner of Azkaban, they are roughly ten feet tall, and located in the Entrance Hall on either side of the door leading to the grounds, as described in the books.
- In all of the Harry Potter films as well as the video games of Order of the Phoenix and Half-Blood Prince, the Hourglasses are located in the Great Hall to the right of the staff table.
- There is possible symbolism in that when Albus Dumbledore died in Harry Potter and the Half-Blood Prince, the Gryffindor hourglass was smashed (spilling blood-red rubies everywhere) and likewise, when Lord Voldemort was defeated in Harry Potter and the Deathly Hallows, it was the Slytherin hourglass that was shattered.
- The hourglasses are also featured at the entrance in the Hogwarts castle in The Wizarding World of Harry Potter. They show that Gryffindor is in the lead, Slytherin second, Hufflepuff third, and Ravenclaw last in achieving house points. Ironically, Ravenclaw students are famous because of their wisdom, creativity, and intelligence, some of the factors that apply to earning house points.
- Harry Potter and the Philosopher's Stone (First appearance)
- Harry Potter and the Philosopher's Stone (film)
- Harry Potter and the Philosopher's Stone (video game)
- Harry Potter and the Chamber of Secrets (film)
- Harry Potter and the Chamber of Secrets (video game)
- Harry Potter and the Prisoner of Azkaban (film)
- Harry Potter and the Prisoner of Azkaban (video game)
- Harry Potter and the Goblet of Fire (film)
- Harry Potter and the Order of the Phoenix
- Harry Potter and the Order of the Phoenix (film)
- Harry Potter and the Order of the Phoenix (video game)
- Harry Potter and the Half-Blood Prince
- Harry Potter and the Half-Blood Prince (film)
- Harry Potter and the Half-Blood Prince (video game)
- Harry Potter and the Deathly Hallows
- Harry Potter and the Deathly Hallows: Part 2
- Harry Potter and the Deathly Hallows: Part 2 (video game)
- LEGO Harry Potter: Years 1-4
- LEGO Harry Potter: Years 5-7
- The Wizarding World of Harry Potter