How long should I realistically expect to wait for a Letter of Recommendation from my previous university?

The variable that actually decides your timeline is not how well you know the professor, it is whether your institution routes Letters of Recommendation through a formal administrative process or leaves the professor to write and submit it directly.

Why Administrative LORs Take Longer Than Professor Written Ones

Where a professor writes and submits your LOR personally, turnaround commonly runs 1 to 3 weeks, particularly if you give them a complete package upfront. Where a department requires review or formal sign off before the letter is finalized, add several working days to a few weeks on top of the writing time itself. Some institutions publish very specific internal timelines, ranging from collection after as little as 1 working day at some colleges to considerably longer at others with a heavier approval chain, so there is real variation even within India. A recommender who is genuinely busy, or receiving many requests during peak application season, can easily push the wait to 4 to 6 weeks or more, which is exactly why most universities recommend asking at least 3 to 4 weeks ahead, and some recommend 6 to 8 weeks.

A Backwards Planning Timeline From Your Deadline

If your application deadline is 1 December, do not wait until November to ask. A safer sequence looks like: request the letter about 6 to 8 weeks out with your CV, transcript, SOP draft, and program details attached; send one polite follow up if nothing has moved after 2 to 3 weeks; confirm around 2 weeks before the deadline that it has actually been submitted, not just promised; and leave at least 1 week of buffer before the deadline to catch any portal issues on the recommender's side.

My Advice

In my experience, students underestimate how many separate LOR submissions one recommender juggles during peak season, especially if you are applying to multiple universities that each require the letter submitted through their own portal. Give your recommender everything they need in one package the first time, rather than trickling details over several emails, since that alone often shaves a week or more off the real turnaround.