Plural for "distance"?

Hello - I am writing a puzzle about Russian spies in New York and am having some difficulty figuring out the correct plural term in Russian to use for "distances".

Right now I am using расстояний

But most of the online dictionaries I find are translating this as "distance".

When I lop off the last character, making the word расстояни

The online dictionaries then translate it as "distances".

This is counter-intuitive to me, and I was wondering if I was doing anything wrong...

Is расстояний the plural term, translating to "distances", or have I gotten myself horribly confused?

Thank you very much!

Do you know about case system in Russian? Each noun in Russian should take one of six cases (for both single and plural) according to its role in a sentence. Each case has specificity in spelling. It is like in English "I" and "me", "We" and "us".

Here are all forms of the word "расстояние".

Basically it means that you can not correctly translate one word from a sentence. You need to translate the whole sentence.

The "default" case (which is used in vocabularies) is nominative. Nominative plural of this word is "расстояния".

Thank you, that is very helpful!

The sentence I am trying to translate in full is "Calculate the distances." The intent of the message is that it's an instruction from a master spy to one of the agents in his network. I currently have:

"Рассчитай расстояний."

Does that sound like functional Russian?

While I don't know if I am using the correct case, it is heartening to see on the table you linked to that at least "расстояний" is the plural form of *one* of the cases.

Correct form is "Рассчитай расстояния".
The following sounds better to me "Вычисли расстояния".

I would say "рассчитай расстояния" or "определи дистанции" (e.g. to your targets), depending on context. "Вычисли расстояния" has a connotation of a pure mathematical task ("calculate / compute distances by given input parameters").

This is all very fantastic. Thank you very much!