Раз уж ты уже считаешь бюджет, запиши и вес коробок, и их объём.

Раз уж is a conversational expression meaning something like:

• since
• if you’re already...
• given that...

In this sentence, Раз уж ты уже считаешь бюджет... means:

• Since you’re already calculating the budget...
• If you’re doing the budget anyway...

It often introduces a suggestion or an extra task that naturally follows from what someone is already doing.

They do different jobs.

1. уж inside раз уж is part of a fixed expression.
   In modern Russian, learners usually treat раз уж as one chunk meaning since / if you’re already at it.

2. The second уже keeps its normal meaning: already.

So:

• Раз уж = since / given that
• уже считаешь = are already calculating

That is why both can appear in the same sentence without being a mistake.

Yes, считать can mean to count, but it also often means:

• to calculate
• to work out
• to estimate

So считать бюджет here is not literally count the budget. It means something like:

• calculate the budget
• work out the budget figures

Russian считать is broader than English count.

Because the speaker is talking about an action that is already in progress or currently happening.

• считаешь = imperfective, present tense
  you are calculating / you calculate

The phrase ты уже считаешь бюджет implies: you’re already in the middle of doing this.

If you said посчитаешь, that would usually mean you will calculate or you calculate it once/to completion, which does not fit as well with already doing it now.

This is a classic aspect difference.

• запиши = perfective imperative
  write it down / make sure to write it down
• записывай = imperfective imperative
  be writing it down / write it down regularly / keep writing it down

Here the speaker wants one completed result: note down the information. So perfective запиши is the natural choice.

It is in the accusative, but for many masculine inanimate nouns, the accusative looks exactly like the nominative.

• nominative: бюджет
• accusative: бюджет

So in считаешь бюджет, бюджет is the direct object, but its form does not visibly change.

The same thing happens with объём in запиши ... объём:

• nominative: объём
• accusative: объём

Because after a noun like вес (weight), Russian commonly uses the genitive to show the weight of something.

So:

• вес коробок = the weight of the boxes
• объём коробок = the volume of the boxes

Here коробок is genitive plural of коробки.

Compare:

• коробки = boxes (nominative plural)
• коробок = of boxes (genitive plural)

This is the Russian pattern и ..., и ..., which means:

• both ... and ...

So:

• запиши и вес коробок, и их объём = write down both the weight of the boxes and their volume

This structure is very common and natural in Russian.

Их means their.

So их объём = their volume.

Russian often avoids repeating the noun if it is already clear from context. The sentence could have said:

• и вес коробок, и объём коробок

But that sounds more repetitive. Using их makes it smoother:

• и вес коробок, и их объём

This is a great question, because Russian often uses свой for reflexive possession. But here их is more natural.

Why? Because the subject is ты (you), while the boxes belong to the boxes themselves only in the sense that we are talking about the boxes’ volume. The possessor is not the subject ты.

• свой usually refers back to the subject of the clause.
• Here, the subject is ты, but the volume belongs to коробки, not to ты.

So:

• их объём = their volume = the volume of the boxes

Using свой here would point back toward ты, which would be wrong or confusing.

Yes, it could be omitted.

Russian often drops subject pronouns when they are clear from the verb ending:

• Раз уж уже считаешь бюджет... would sound awkward because of the double ужe placement, but
• Раз уж считаешь бюджет, запиши... is perfectly possible.

Including ты can add:

• a slightly more direct tone
• a bit of emphasis
• a conversational feel

So ты is not required grammatically, but it is natural here.

The word order is flexible but meaningful.

Раз уж ты уже считаешь бюджет, запиши и вес коробок, и их объём.

This order feels natural because it goes:

1. background situation: since you’re already calculating the budget
2. main instruction: write down...
3. the two items: the weight and the volume

Putting уже before считаешь emphasizes that the action is already underway.

Putting и вес коробок, и их объём after запиши makes the instruction clear and balanced.

Их here is a possessive form meaning their.

In их объём, the whole phrase их объём is the direct object of запиши. The noun объём is in the accusative, but for an inanimate masculine noun, that looks like the nominative.

The word их itself does not change form here. Russian их can mean:

• them (object pronoun)
• their (possessive)

Here it is possessive: their volume.

Yes. Russian ё is often written as е in ordinary text, so you may see:

• объём
• объем

Both represent the same word.

But using ё is helpful for learners because it shows the correct pronunciation more clearly:

• объём sounds roughly like ab-YOM

So the sentence may also appear as:

• Раз уж ты уже считаешь бюджет, запиши и вес коробок, и их объем.

That is normal spelling practice in Russian.

Yes. A very literal version is:

• Since you’re already calculating the budget, write down both the weight of the boxes and their volume.

But depending on context, more natural English versions could be:

• If you’re already working out the budget, make a note of the boxes’ weight and volume too.
• Since you’re doing the budget anyway, write down both the boxes’ weight and their volume.
• While you’re calculating the budget, note the weight and volume of the boxes as well.

That reflects the conversational tone of раз уж and the instruction implied by запиши.