Approximately how often do you go through an ounce of ink?

How much do you write, and what is your pen nib like?

Broader nibs use more ink than fine nibs.
Some nibs are wet, using a lot of ink for the size, and some are dry, using less ink.
Also some inks are wet, and will flow a lot through your nib, others are dry, and will flow less through your nib.

A broad, wet nib with a wet ink will write many fewer pages per ounce than a fine, dry nib with a dry ink.

I know it is a very personal thing. I'm not asking how much I will go though. I'm asking how much each of you goes through.

Don't know yet, I'm new to bottled inks! Probably fairly slowly, as I will have to have a bunch of different inks around.

I'm using a Pelikan M800 and Toledo. Both with OB nibs. I rotate the pens once the ink is depleted. Average time in between fills is between 10 to 14 days. If I'm going for a full day conference or a business trip, I top up the pen for good measure. It took me about 3 years to nearly empty the bottle of Pelikan 4001 ink. When it was near the end, it was very hard to fill the pens. I started on a new bottle and when the ink level was down sufficiently, I poured the reminder of ink from the old bottle into the new one. Pelikan ink bottles are 62.5ML.

To be fair, I let back 5 drops of each after each refill.

The only pen I have extensive experience with is my Waterman 52V, and it holds a good deal of ink. It's not until five pages or so of solid writing that I may become worried about having to fill it again. I used mainly Pelikan 4001 Royal Blue and Noodler's La Coeleur Royale in it. My bottle of 4001 is about 5/8th empty and the LCR has a good 2/3 left. To be fair, I wasted quite a bit of ink, so I'll say I've used about 32ML of 4001 and 25ML of LCR in the course of four months.

Writing activities included note taking, essay writing, and letter writing (for leisure).

Using my Safari F maybe...half an hour? a day, I've still got at least half of my current bottle of Aurora.
I think it's a fairly small bottle, so I guess I don't use much.

I'll maybe use an ounce in a month on average, I'd say.

My Montblanc writes rather wetly and goes through ink pretty fast. So if I'm using it, I always keep a bottle of ink nearby. It's run dry on me three times already when I wasn't expecting it.

I can't answer that question because I have around 30 inks and rotate between all of them, so it's hard to gauge my consumption rate. I imagine that most of the Inky Thoughts readers are also such ink addicts, though there have been a number of threads where people report such numbers. I think there was a thread with "mileage" in the title, but search "rate" and "usage" in the titles also (and if you still haven't found anything, in the body, but only in "inky thoughts").