I occasionally track my work time for a few weeks at a time; by coincidence I happen to be tracking it at the moment. I used to use Toggl; currently I just track my time in my notebook by noting the time whenever I start and stop working (where by "working" I mean "actively focusing on work stuff"). I am more careful about time tracking my work on my day job (working on longtermist technical research, as an individual contributor and manager) than working on the EAIF and other movement building stuff.
The first four days this week, I did 8h33m, 8h15m, 7h32m, and 7h48m of work on my day job. I think I did about four hours of work on movement building. So that's an average of about 9 hours a day. Probably four of those hours are deep work on average.
My typical schedule is to do movement building stuff first thing in the morning, eg perhaps 7:30am to 8:30am, and then to do my day job between about 8:30am and 7pm, with a 30m break at 10am to hang out with my girlfriend after she's woken up, and a maybe 40m break for lunch at about 12:10. I occasionally do some calls in the evenings, or respond to people's messages about work things. (I usually go to bed between 10:10 and 11pm.)
So my efficiency is probably about two thirds, if you include my morning break and lunch break in the denominator, and 75% if you don't.
I normally work for a couple hours on the weekend, mostly doing calls, and I also usually do some kind of unstructured and unfocused work like walking around and thinking about lots of stuff which sometimes includes my work. So I guess my total work time per week is probably like 47 hours or something.
My efficiency is highest when I wake up unusually early and work uninterrupted for a long time. It's also much higher when I'm doing tasks that it's easy to do for a long time. The most obvious example of this is meetings--they require less concentration than e.g. programming, and so if my day includes a lot of meetings, my efficiency looks higher.
Of course, work efficiency is a dangerous thing to optimize--I actually want to optimize the value of my work output, which is related but importantly different. In particular, sometimes I fall into a trap where I spot some task which I can easily spend lots of time on, but which isn't actually the most valuable. I try hard in this kind of situation to catch myself and ask "what's actually the most important thing to do right now".
My efficiency and total work time has usually been somewhat lower in the past. When I worked at MIRI, I would typically get something like 37 hours of work done in a typical week (roughly 2/3 technical work and 1/3 recruiting work). I also had some bad fatigue problems at various points over the last few years; I think I worked more like 20 hours per week for like a third of 2019, which was very sad and unpleasant. I was kind of depressed for a while last year, which I think took my work down to maybe 30 hours per week. I work more at my current job for a few reasons: it feels more tractable than my MIRI work, I feel more responsibility because I have a more senior role, and I am working more as a manager and so I spend more time doing types of work that I find less tiring.
I think that my current work schedule is basically sustainable for me as long as I feel reasonably happy and satisfied with my life, which is pretty hard for me to ensure.
I can imagine taking other jobs that seemed equally impactful where I'd end up working many fewer hours. And there are a few jobs where I'd end up working more hours (eg jobs where I was constantly talking to people and rarely trying to think hard about stuff).