"These straightforward but surprisingly dangerous charms cause certain things to swell or shrink. You will be learning both charms together, so that you can always undo an over-enthusiastic cast. There is thus no excuse for having accidentally shrunk your homework down to microscopic size or for allowing a giant toad to rampage through your school’s flower gardens."
Miranda Goshawk[src]

The Shrinking Charm[2] (Reducio)[1] is a charm that causes an object to shrink.[2] It is the counter-charm to the Engorgement Charm, causing enlarged objects to return to their original size.[1] The Shrinking Charm is also used as the potion-making spell for the Shrinking Solution.[3]

The use of a Shrinking Charm on a human is considered both complicated and dangerous.[4]


During the 1985–1986 school year, the Shrinking Charm was covered in second year charms classes at Hogwarts School of Witchcraft and Wizardry.[4]

Known practitioners and uses

Caster(s) Date Notes
Jacob's sibling 1985–1986 school year Jacob's sibling used an Engorgement Charm alongside the Shrinking Charm to sneak into another House common room.[4]
Mortlake and Wizarding Pranksters July and August 1992 Mortlake and some pranksters used a Shrinking Charm on some door keys. They were arrested by Arthur Weasley and sent to Azkaban.[5]
Accidental Magic Reversal Squad July 1993 The Accidental Magic Reversal Squad was called when Harry lost his temper and non-verbally cast an Engorgement Charm on Marge causing her to inflate. They shrank her back to her normal size and gave her and The Dursleys a Memory Charm.[6]
Arthur Weasley August 1994[7]
Barty Crouch, Jr September 1994 The fake Moody, who had enlarged a spider with an Engorgement Charm, used this to return it to its normal size.[1]
Poppy Pomfrey October 1994 When Hermione Granger was hexed by Draco Malfoy, her front teeth grew huge. Madame Pomfrey shrunk her teeth with this spell. Hermione used this occasion to avoid having braces because her teeth were originally larger than normal teeth and caused her to be compared to a chipmunk by other students.[8]
Harry Potter 27 December, 1997 Harry, who had enlarged a spider with an Engorgement Charm with another's wand, tried to use this to return it to its normal size, but it didn't work. Later, he used it after he enlarged a lamp fire after he got another wand.[9]


The incantation is a Latin word meaning "to reduce" or "is reducable", fitting for this spell's effects[10].

Behind the scenes

See also


Notes and references

  1. 1.0 1.1 1.2 1.3 1.4 Harry Potter and the Goblet of Fire, Chapter 14 (The Unforgivable Curses)
  2. 2.0 2.1 2.2 2.3 2.4 Wonderbook: Book of Spells
  3. Wonderbook: Book of Potions
  4. 4.0 4.1 4.2 Harry Potter: Hogwarts Mystery, Year 2, Chapter 2 (Growing and Shrinking) - Charms Lesson "Reducio"
  5. Harry Potter and the Chamber of Secrets, Chapter 2 (Dobby's Warning)
  6. Harry Potter and the Prisoner of Azkaban, Chapter 4 (The Leaky Cauldron)
  7. Harry Potter and the Goblet of Fire, Chapter 4 (Back to The Burrow)
  8. Harry Potter and the Goblet of Fire, Chapter 18 (The Weighing of the Wands)
  9. Harry Potter and the Deathly Hallows, Chapter 20 (Xenophilius Lovegood)
  10. See this translation, courtesy of Google Translate

Charms (class)
PS Wingardium Leviosa feather
Charmbook writers and developers
Delfina Crimp · Miranda Goshawk · Jarleth Hobart · Basil Horton · Randolph Keitch ·
Levina Monkstanley · Orabella Nuttley · Mnemone Radford · Scarpin · Elliot Smethwyck ·
Felix Summerbee · Fred Weasley · George Weasley
Professors Fortinbras · Filius Flitwick
Textbooks The Standard Book of Spells · Achievements in Charming · Quintessence: A Quest
Charms studied at Hogwarts
Banishing Charm (Depulso) · Cheering Charm · Cistem Aperio · Colour Change Charm (Colovaria) · Dancing Feet Spell (Tarantallegra) · Engorgement Charm (Engorgio) · Exploding Charm (Bombarda) · Fire-Making Spell (Incendio) · Freezing Charm (Immobulus) · Freezing Spell (Glacius) · Full Body-Bind Curse (Petrificus Totalus) · General Counter-Spell (Finite Incantatem) · Growth Charm · Hardening Charm (Duro) · Knockback Jinx (FlipendoLevitation Charm (Wingardium Leviosa) · Locomotion Charm (Locomotor) · Mending Charm (Reparo) · Memory Charm (Obliviate) · Nonverbal spell · Red Sparks (Vermillious) · Reductor Curse (Reducto) · Seize and Pull Charm (Carpe Retractum) · Severing Charm (Diffindo) · Shrinking Charm (Reducio) · Silencing Charm (Silencio) · Slowing Charm (Arresto Momentum) · Skurge Scouring Charm (Skurge) · Softening Charm (Spongify) · Spell for growing legs · Substantive Charm · Summoning Charm (Accio) · Tickling Charm (Rictusempra) · Unlocking Charm (Alohomora) · Vinegar into Wine · Wand-Extinguishing Charm (Nox) · Wand-Lighting Charm (Lumos) · Water-Making Spell (Aguamenti)