Kontraktor memperkirakan waktu renovasi.

It follows the standard Indonesian Subject–Verb–Object order:

• Kontraktor = subject
• memperkirakan = verb
• waktu renovasi = object

So it works very much like English The contractor estimates the renovation time.

Indonesian does not usually use articles like the or a/an.

So:

• kontraktor can mean a contractor or the contractor
• waktu renovasi can mean renovation time, the renovation time, or the time for the renovation

The exact meaning depends on context. If you want to make something more specific, Indonesian often does that through context or words like itu.

For example:

• Kontraktor itu memperkirakan waktu renovasi. = That/The contractor estimates the renovation time.

Memperkirakan means to estimate, to predict, or to calculate roughly.

In this sentence, it most naturally means estimate.

It comes from the root kira, which is related to guessing, estimating, or thinking approximately. The longer form memperkirakan sounds more formal and transitive, meaning it takes an object:

• memperkirakan waktu = to estimate the time

It is formed from the root kira with the affixes memper- and -kan:

• kira = estimate / guess
• memperkirakan = to estimate something

This is a common Indonesian pattern for making an active verb that acts on an object.

A learner does not always need to fully analyze every affix at first, but it helps to recognize that:

• memperkirakan is an active verb
• it normally takes an object after it

That is why waktu renovasi comes after it.

Because kira by itself is usually not used in this sentence as the main formal verb in the same way.

Compare:

• Saya kira dia sudah datang. = I think he has already come.
• Kontraktor memperkirakan waktu renovasi. = The contractor estimates the renovation time.

So kira often behaves more like think / suppose, while memperkirakan is better for estimating something such as time, cost, or numbers.

Waktu renovasi literally means renovation time.

In natural English, depending on context, that could mean:

• the time needed for the renovation
• the duration of the renovation
• sometimes the schedule/timing of the renovation

Most likely here, it means how long the renovation will take.

If you want to be more explicit in Indonesian, you could also say:

• waktu yang dibutuhkan untuk renovasi = the time needed for the renovation
• lama renovasi = the duration of the renovation

Because Indonesian often links nouns directly, where English might use of, for, or a compound noun.

So:

• waktu renovasi = renovation time / time for renovation
• biaya renovasi = renovation cost
• jadwal renovasi = renovation schedule

This noun + noun structure is very common in Indonesian.

Here, renovasi is functioning as a noun.

In Indonesian, many borrowed words like renovasi can act as nouns in phrases like:

• waktu renovasi = renovation time
• biaya renovasi = renovation cost

If you want the verb to renovate, Indonesian often uses:

• merenovasi = to renovate

For example:

• Kontraktor merenovasi rumah itu. = The contractor renovates/is renovating that house.

So in your sentence, renovasi is not the verb. It is part of the object phrase.

No. Indonesian verbs do not change form for tense the way English verbs do.

So memperkirakan by itself does not tell you whether it is:

• estimates
• is estimating
• estimated
• will estimate

The time reference comes from context or extra time words.

For example:

• Kontraktor memperkirakan waktu renovasi. = could be present, depending on context
• Kemarin kontraktor memperkirakan waktu renovasi. = Yesterday the contractor estimated the renovation time.
• Besok kontraktor akan memperkirakan waktu renovasi. = Tomorrow the contractor will estimate the renovation time.

It is a loanword, and it means contractor.

Indonesian uses many loanwords, especially for business, construction, and technical topics. Kontraktor is completely normal and common.

Your original sentence is understandable, but if you want to express that idea more clearly and naturally, Indonesian speakers might also say:

• Kontraktor memperkirakan lama renovasi.
• Kontraktor memperkirakan berapa lama renovasi akan berlangsung.
• Kontraktor memperkirakan waktu yang dibutuhkan untuk renovasi.

These are slightly different in style:

• lama renovasi = concise, often very natural for duration
• berapa lama ... = very explicit: how long
• waktu yang dibutuhkan untuk renovasi = more formal and precise

A rough pronunciation guide is:

• kontraktor → kon-trak-tor
• memperkirakan → mem-per-ki-ra-kan
• waktu → wak-tu
• renovasi → re-no-va-si

A few helpful notes:

• Indonesian r is usually trilled or tapped, not like most English r
• vowels are usually pronounced clearly
• stress is not as strong or dramatic as in English

So the sentence is roughly:

kon-trak-tor mem-per-ki-ra-kan wak-tu re-no-va-si

Yes, depending on nuance.

Some possibilities:

• menaksir = to estimate, often for price, amount, or value
• mengira = to think / suppose / guess
• memprediksi = to predict

Examples:

• Kontraktor menaksir biaya renovasi. = The contractor estimates the renovation cost.
• Saya mengira renovasinya cepat selesai. = I thought the renovation would finish quickly.

For your sentence, memperkirakan is a very good choice because it fits the idea of estimating time.