You know you overbuilt your rocket when...

[tetryds]

When the spare part of your lifter becomes a fuel station because steering it was too boring.

[Lhathron the Elf]

When the spare part of your lifter becomes a fuel station because steering it was too boring.

Me all of the time.

[NecroBones]

.. when you manage to land on 2 or 3 more planets/moons than the mission originally called for, and still have enough fuel to get home.

[Alchemist]

When you barely have 6 FPS... after reaching the orbit. And it's just a part of your mothership

.. when you manage to land on 2 or 3 more planets/moons than the mission originally called for, and still have enough fuel to get home.

When you guestimate the capabilities as "Jool-5 plus-minus Eeloo and Dres" (and get exactly this upper limit in the end)

[Franklin]

A landing attempt with LV-Ns is always the sign of an over-engineered rocket.

[Pecan]

When your 'light' ship is 130kg heavier than 5thHorseman's

OK, so it's no behemoth, but over-building is all relative! Guess what I'm spending my evening doing.

[Lichbane1401]

When you lift a 1000 part space station into orbit with one launch with just 1-2 fps

When you use 5 KW Saturn V main engines for you last stage

Edited November 7, 2014 by Lichbane1401

[bs1110101]

When you have a mostly full stage, and bring it along for extra fuel, in RSS!

[Yakky]

When your rocket is so heavy it destroys the pad... but is still intact afterward.

[LABHOUSE]

When your twr is more than 1.2 on the last stage.

[Xavven]

...when you get re-entry flames during liftoff.

[Norpo]

...when it lands on the Mun, and it still has solid boosters.

[Master Tao]

One of your boosters explodes seconds after liftoff... and you still reach your target orbit.

[technicalfool]

One of your boosters explodes seconds after liftoff... and you still reach your target orbit.

...after at least 1080 degrees of cartwheeling and jetissoning the other boosters to even out your centre of thrust.

[Vaporo]

A landing attempt with LV-Ns is always the sign of an over-engineered rocket.

Since you said this, I have am now obligated to post the Tylo lander from my Jool-5 mission.

Your rocket is overbuilt when you can destroy a mainsail on your lifter stage and have the difference made up for by thrust vectoring.

[Rakaydos]

Too many kerbals when the clipped command seats start sending them into the air before you get into the air.

Edited November 8, 2014 by Rakaydos

[Jr6150x]

When your rocket begins to look like some thing whack job would conjure up

[NecroBones]

When you barely have 6 FPS... after reaching the orbit. And it's just a part of your mothership

When you guestimate the capabilities as "Jool-5 plus-minus Eeloo and Dres" (and get exactly this upper limit in the end)

That's almost exactly what I had in mind. My Jool-5 ended with visiting Dres, Mun, and Minmus.

[GiantTank]

When you design a rocket, design a rocket to lift that rocket, design a rocket to lift THAT rocket. Rocket^4=Kraken.

[Aragosnat]

When you can build craft like Whackjob.

[Mesons]

... and the circularization burn, ... and part of the landing burn, ... and you only stage because this part of the rocket was never meant to land.

Enter half of my Mun/Minmus/Duna rockets...

[zxczxczbfg]

. . . When you accidentally hit spacebar and release the first-stage boosters a few minutes too early, and decide "eh screw it, I didn't need those anyway".

(SSTO: Superfluous Stages to Orbit.)

[Whackjob]

When your Munar lander alone is larger than most rockets.

[Nemrav]

when Whackjob himself admits it might be slightly on the small side, I mean really only 2 vabs' tall ?

That might be interresting come to think of it.....

[Frank_G]

...when your SRB powered munar transfer ends in a Jool encounter...