Meaning & use
crap in crap out
Last updated
Meanings
phrasefixed phraseinformalfigurative
Bad or poorly prepared input produces bad results, so the quality of what comes out depends on what went in.
Grammar: Used as a complete statement or as a noun-like phrase: you say the phrase rather than changing its parts.
Patterns
- crap in, crap out
- it's crap in, crap out
The report is full of errors because nobody checked the figures they typed in — crap in, crap out.
If you feed the model sloppy data, you get sloppy answers; crap in, crap out.
Our manager keeps saying crap in, crap out whenever a project starts with a vague brief.
phrasefixed phraseinformalcomputing
In computing, a rule or saying that faulty data entered into a system will make the system's output faulty too.
Grammar: Often written with commas and used as a short principle or warning about data quality.
Patterns
- crap in, crap out
Programmers often quote crap in, crap out when a database is filled with unchecked entries.
The training course began with crap in, crap out to show why clean data matters.
Common combinations
- crap in, crap out
- The spreadsheet was a mess, and the final chart proved crap in, crap out.
- it's crap in, crap out
- The teacher warned us: it's crap in, crap out, so read your sources carefully.
- a crap in, crap out situation
- With so many missing records, we were stuck in a crap in, crap out situation.
- crap in, crap out principle
- The crap in, crap out principle explains why the survey results were useless.
Synonyms and how they differ
- garbage in, garbage out
- The standard, more polite version of the same idea; use it in formal writing, reports, or when speaking to customers.
- rubbish in, rubbish out
- The common British equivalent; it sounds slightly less crude in British English but is still informal.
Word family
Commonly confused: crap in crap out or garbage in, garbage out?
crap in crap out vs garbage in, garbage out
This is the standard, non-offensive form of the same saying; 'crap in crap out' is the crude version, so choose according to your audience.
Practice
A colleague says the sales forecast is unreliable because the original figures were wrong. Which sentence uses the phrase correctly?
Choose one answer.
The phrase works as a fixed statement or noun-like phrase, so 'because of crap in crap out' fits. Option 1 is wrong because the phrase describes bad input causing bad output, not careful checking; options 2 and 3 treat it as a verb, which it is not.
Make it your own
Write a sentence using “crap in crap out”, then check it and compare it with the examples above.