"Hey, Ferb! I know what we're gonna do today!"
— Phineas.

Almost every day during their summer vacation, Phineas Flynn and Ferb Fletcher have Big Ideas and go through with them. Some of the plans are used as a way of helping someone in need, while others are just to help them have the best possible summer ever, as described in "Rollercoaster" and "Rollercoaster: The Musical!".

Season 1

Main article: Big Ideas/Season 1

Season 2

Main article: Big Ideas/Season 2

Season 3

Main article: Big Ideas/Season 3

Season 4

Main article: Big Ideas/Season 4


Episode Image Big Idea Disappearance Notes
Camp Rock 2: The Final Jam Its On Phineas and Ferb directed the Summer version of the music video "It's On" from "Camp Rock 2: The Final Jam" kicking off Disney Channel's Summer Vacation. The video ends with the entire party leaving the boardwalk. The first time crossover meet Cast of Camp Rock 2: The Final Jam.
Phineas and Ferb The Movie: Across the 2nd Dimension Platypult ready to be usedPFBigIdeas The boys made a platypult to play badminton with Perry. Then they go on a grand adventure through a parallel universe with Agent P in agent form and try to defeat Alternate Doofenshmirtz. To save the Tri-State Area, Phineas and Ferb recreated many of their previous inventions to fight off the Norm bots. The platypult is the only new big idea to appear in the film. The previous big ideas were piloted by the kids of Danville.
The Phineas and Ferb Effect Screenshot 20190123-195148 YouTube Brothers made Murphy's Law Suit in order to defeat Phistachions. It was created after the charachters learned about The Phineas and Ferb Effect. In order for it to work, Milo, Phineas, and Ferb should be together in this machine.

Background Information

  • The plans the boys come up with can be described as impossible because they are accomplished in a very short amount of time (less than a morning {they use the invention in the afternoon, most likely}) and involve technology that has yet to exist in the real world: teleportation, mind-switching, time traveling... Phineas and Ferb do not think of their plans as impossible, just fun and great. When Isabella asks Phineas if building a time machine is "kind of impossible", he replies, "That's a possibility". ("It's About Time!")
  • The phrase "Big Ideas" references the advertising campaign that Disney Channel ran prior to the launch of the series in February 2008. For Phineas, it was "he thinks big". For Ferb, it was "he thinks how".
  • Despite Phineas saying that he likes to "keep moving forward", he actually has repeated his big ideas. Examples are the rollercoaster in "Rollercoaster", "Fireside Girl Jamboree", "Phineas and Ferb-Busters!", and "Rollercoaster: The Musical!"; the waterslide in "Leave the Busting to Us!" and "Elementary My Dear Stacy"; the molecular seperator in "Split Personality" and "Canderemy"; and the time machine in "It's About Time!" and "Phineas and Ferb's Quantum Boogaloo."
  • Phineas and Ferb have been busted five times on-screen.
    • It was all Candace's dream in Perry's dream ("Phineas and Ferb Get Busted").
    • Older Candace busted them while building the Rollercoaster, which has been undone by herself after she saw that this would lead to a dystopian society run by Emperor Doofenshmirtz. This happened in another universe. Later, Candace busted them by showing herself to future mom, but this has probably been undone by Isabella when she went back in time and made the entire episode undone during the credits. Along with the fifth time they were busted, this happened in another universe ("Phineas and Ferb's Quantum Boogaloo").
    • When they built a pioneer village, but that was undone when the acceleratorinator moves time backwards ("She's the Mayor").
    • Once Candace succeeds in busting them briefly, however her mother is hit with Doofenshmirtz's "Forget-About-It-Inator" repeatedly and by the time she is no longer being hit by the ray, Candace has ran off and the boy's invention isn't in view so she returns inside ("A Real Boy").
    • Linda "busts" Phineas and Ferb herself due to them leaving towels all over the ground. ("Love at First Byte")
  • However, there are other times where Phineas and Ferb's plots have been seen by their parents, a famous example being in "Dude, We're Getting the Band Back Together" among others, however they weren't "busted" for them (assuming "busting" implies that they were intentioned to get in trouble for whatever they're doing). Their dad has also seen and has been involved in some of their big ideas, but it doesn't seem he minds and Candace almost never gets her dad to bust them which implies the busting power is from their mom.
    • One famous example is during Mom's birthday, because on that day she saw everything they built ("Mom's Birthday")
    • Mom saw the teleporters but due to the effects of Doofenshmirtz's Shrinkinator, she thinks they're earrings the boys made her ("Does This Duckbill Make Me Look Fat?").
    • Their Mom actually sees Nosebud and says that it's "pretty cool" because it actually floats, but does not know about the station under it ("The Lake Nose Monster").
    • Mom saw the animal translator, only to her Phineas and Ferb were just using some sort of recording machine because it didn't work on Perry ("Interview With a Platypus").
    • Mom saw only the top portion of the fort (and not the other giant parts of it). Upon seeing this, she remarks on how Phineas and Ferb are "beginning to take an interest in building things" ("Thaddeus and Thor").
    • Mom saw Phineas and Ferb's creation, only Phineas and Ferb were gone and she thought it was some kind of modern art ("The Bully Code").
    • Mom saw Phineas and Ferb's Backyard Hodge Podge made out of recycled parts, but thought she was hallucinating, and Candace cannot see it clearly after being hit by Doofenshmirtz's Eye Fog-inator ("Backyard Hodge Podge").
    • Mom saw the jumbotron to Phineas and Ferb's Ultimate Obstacle Course, but because of the picture of the boys on the monitor, she assumes it's just the boys and leaves ("One Good Turn").
  • Also, there are other times where the plots were seen by Phineas and Ferb's parents, a good example being in "The Best Lazy Day Ever", however Candace built a dinosaur slide in that episode.
    • They built something in "Perry Lays an Egg", but Candace was the one who got in trouble.
    • Phineas and Ferb built a Latest Technology All-Terrain Vehicle in The Secret of Success, but it was Candace who got into trouble as she said that she drove it herself and Mom shouts at her that she drove a car without any adult surveillance.
    • Phineas and Ferb didn't do anything in "Candace Gets Busted". But when Mom and Dad see that Candace is having the party (the Intimate Get Together), Candace is the person busted.
  • Lawrence Fletcher has seen many of Phineas and Ferb's creations, but hasn't busted them.
  • The only times the boys don't come up with a big idea were in "The Best Lazy Day Ever", "Vanessassary Roughness", and "Candace Gets Busted".
Community content is available under CC-BY-SA unless otherwise noted.