Is there an American English equivalent of the British idiom "carrying coals to Newcastle"?

I've heard of the phrase "bringing sand to the desert". I'm from the west coast of the United States. I'm not sure how common it is, but I feel like a native speaker would understand the intended meaning (as with many of the other examples provided on this thread).

Many of the answers given here have involved futile tasks, that are either impossible to complete, or will be immediately undone. They're missing the point of the original question. I wouldn't call carrying coals to Newcastle exactly a futile task. It's certainly easily possible to do, but the point is that it's completely unnecessary and pointless, and therefore a waste of effort.

Phrases such as teaching your grandmother to suck eggs (unnecessary, she already knew how to do that) and rearranging the deck chairs on the Titanic (a pointless task, as they'll be in the drink soon enough) are my favorites among all those mentioned, but may not be of American origin.

"Ass-backwards."

"Carrying coals to Newcastle" is futile and unnecessary because it is completely the wrong way around. It refers to doing something in the opposite way that it should be done, or in a manner contrary to logic.

I'm not sure it this is American or not but I know of the phrase, "Selling tea to China." which approximates, "Taking coal to Newcastle."

How about "an exercise in futility?" It's not as picturesque of an idiom but it's certainly spot on in expressing "pointlessness" as opposed to "unimportance", "difficulty", or "tediousness" like some of the other answers.

Another I've heard before is emptying the ocean with a teaspoon (or lake or sea or swimming pool).

Not sure how common it is, but it certainly conveys a similar idea of uselessness (although for a slightly different reason than the original carrying coals to Newcastle)

It depends on the context you are using; if you are talking spare time, it might be “watching the tube,” and referring to finances, it might be “robbing Peter to pay Paul”. In the United States, we have so many idioms used each day, that we have new ones we hear all the time. I like to call it writer's or speaker's license. I think that is why people from other countries have problems at times understanding us, because they take us literally, instead of figuratively. An example would be to “kick the bucket”.

I think you should just say "this is like carrying water to the sea." The meaning is clear, regardless of what language or culture you say it in.

The fact that it isn't a common expression may actually make it more effective.

"Go find you a white crayon and color a fucking zebra" - This lyric from Eminem's song "My Mom" (off of his Rehab album), represents the ultimate in futile efforts: coloring a black and white coloring book white.

I once attended a technical presentation near Tektronix headquarters in Beaverton, Oregon. The presenter was from the UK, and for some odd turn of events, his company had actually moved some coal towards Newcastle once.

The best part was that after having made the reference, later in his presentation he talked about designing some high-speed oscilloscopes. One of the first clients? Tektronix. (The irony here being that Tek was the world leader in scopes for many decades.)

So the US equivalent could be "selling scopes to Tektronix". :)

I'm from New York, and I've always used "carrying coals to Newcastle". It's not specifically British.

I have read, BTW, that the medieval French equivalent was "bringing wool to England". Apparently English wool was popular in France...

I am familiar with the phrase

• Shovelling sand against the tide.

and it's more colourful cousin

• Shovelling shit against the tide.

Both express that whatever effort you put forth, it's going to be immediately undone ... I think that's a good expression of futility.

I'd use "spinning his wheels" (or yours or hers). I think the implication is that the wheels are moving but you're not going anywhere. I looked it up and the free dictionary says:

spin your wheels (American informal) to waste time doing things that achieve nothing (often in continuous tenses) If we're just spinning our wheels, let us know and we'll quit. See also: spin, wheel Cambridge Idioms Dictionary, 2nd ed. Copyright © Cambridge University Press 2006. Reproduced with permission.

"Carrying water in a sieve." is one I've heard used.

I've also heard the Newcastle, etc.

Programmers tend to use the expressions "yak shaving" and "bikeshedding". These expressions tend to be used in reference to losing view of the big picture and spending inordinate amounts of time on incredibly trivial things.

Another option is "gilding the lily", although it carries a connotation of an activity which occurs after a task should already have been completed, or has already been satisfactorily addressed by other means.

Perhaps EL&U would be the perfect place to coin such a phrase.

• Taking crooks to Washington
• Taking rain to Seattle
• Taking cocaine to Hollywood
• Taking idiots to [name a place]

Along with some of the others already posted, there's "Spitting into the ocean".

Also, if you'd like something slightly more pointed (albeit vulgar), there's pissing into the wind.

Sources:

• Urban Dictionary (Definition 1)

• The Free Dictionary

While not the same connotation, I like "nailing Jello to a tree", which suggests a futile act.

The phrase is in widespread use in America. I suspect that some of those who use it don't really know the origins of the phrase (and have no clue where Newcastle is), but it's in pretty common use.

I've heard "Watering the garden (or lawn) in the rain". The meaning would probably be very clear to most people but I strongly suspect it's not in common usage (except to the few people I know that use it often).

Sisyphean as carrying out a futile task repeatedly like Sysiphus, a Greek mythological figure that was doomed to endlessly roll a boulder up a hill in Hades as a punishment for defying the gods.

"Tilting at Windmills" has a connotation of needless/futile. Although admittedly also with a connotation towards fighting unwinnable battles.

Sisyphean comes to mind as an adjective. This could be extrapolated as "pushing a stone uphill" but it tends to only be properly understood among more academic types, due to its roots being in Greek Mythology.

"Pushing rope" or "pushing a rope uphill" would be the closest thing I can think of that I've actually heard in conversation.

Swimming upstream. I agree with Frustrated. Wrong connotation.

Wiktionary suggests

Bring owls to Athens

which has the same sense as coal to Newcastle, in that there are already lots of owls (supposedly) in Athens. But I've never heard anyone say this and wouldn't have understood it.

One we use commonly in our office is

It's like herding cats.

(To describe getting the academics to submit paperwork on time.)

Alternatively, there is "catching wind in a net" or "trying to empty the ocean with a bucket."

Or you could say it's a wild-goose chase.

These aren't exactly what you're looking for, I think, but they're related.

• Re-arranging deck chairs on the Titanic (a superficial, cosmetic change to something with a major underlying structural problem)
• Teaching grandmother to suck eggs (giving advice to someone who is already an expert on the subject)
• A Chinese fire drill (a large, ineffective, and chaotic activity carried out by a group of people that accomplishes nothing—but note that, as the Wikipedia article points out, this phrase is uncommon today due to the politically incorrect ethnic reference.)

Here are a few:

"Selling ice to an Eskimo"

"Locking the stable door after the horse has bolted." (or) "Shutting the barn door after the horse has gone."

"Preaching to the choir" (a phrase originated by George Bernard Shaw in the play The Simpleton of the Unexpected Isles: A Vision of Judgment)

"Giving a drink of water to a drowning man"

I don't think it’s specifically American, but I have heard the following been used:

• asking the sun not to shine
• beating a dead horse (alternatively, flogging)