That happens when you google idioms in other languages ... you have no clue about the actual usage. And they are usually not one-to-one.

German "das ist mir Wurst" is also a lot weaker than "zero fucks given", at least use something stronger like "das interessiert keinen Arsch" (no asshole cares). Also "zero fucks given" in the sense of "irresponsible, he just does it and doesn't care who gets hurt" doesn't really have an equivalent idiom. Maybe "als druff" (just go full power straight ahead) or something.

I've never heard "als druff" but I'd like to add "das ist mir Latte" as a variant as well as "das ist Jacke wie Hose" ("jacket like trousers", which is more like "potayto, potuhto") and as others have pointed out "das geht mir am Arsch vorbei".

But none of them is an exact match as there's no perfect overlap for all situations to which "zero fucks given" can be applied. Which isn't too surprising as most idioms and even most words don't map 1-to-1 between languages even when they share a common root.

How about "Geht mir am Arsch vorbei"?

"It walks/goes past my ass"

"It's passing by at about the height of my ass"

Yeah, "das ist mir Wurst" doesn't seem strong enough. "Drauf geschissen"/"Scheiß drauf" ("shit on it") maybe? Kinda close to "not giving a shit" (or "fuck") and also kinda works for the irresponsible case, "Er scheißt drauf, ob er jemanden verletzt".

"drauf geschissen" comes close to "zero fucks given"

It is the same in Hungarian. "szarni rá" is the exact translation of the German expression.

Das interessiert keine Sau.

No (female) pig cares about it / No sow cares about it

Even stronger (and more like "zero fucks ..." imho): Das ist (mir) scheißegal ("indifferent as shit" ot something like it).

Yes, scheißegal strikes me as exactly the right translation, and once again there is a single German word for an entire English phrase.

The last one sounds like "send it".

"das ist mir Wurst" may not be as weak as you think - 'Wurst' can also be a euphemism for a large, firm piece of excrement.