I'm having a hard time determining my activity level, therefore wondering if I've calculated the correct TDEE for myself. I was wondering if anyone else has had problems with this and can give any advice.

1. Little to no exercise
2. Light (1-3/week)
3. Moderate (3-5/week)
4. Heavy (6-7/week)
5. Daily exercise

I think my problem with this is: 3-5/week - is that 3-5x 30min sessions, 1 hour? Also in the moderate range - isn't working out 3 days a week or 5 days a week kind of a broad range to be under the same calculation? Sometimes I have the tendency to be over calculated and analytical, so tell me if this scale is simply to be an estimate and I'm just looking too into it. I just feel, since it's important to calculate your TDEE correctly, then shouldn't I determine my activity level as accurately as possible?

Please let me know if you can help me out with mine: I currently figure at the moderate level, but let me know if I am incorrect:

I'm working towards running a 5k, so currently, I am run/walking 3 times a week for about 20-30minutes, M-W-F
I walk at a moderate pace for 30 minutes/ twice per week, T-TH
I do 10-20 minutes of arm/upper body weight training/ twice per week (time depends on intensity) T-TH
I do 10-20 minutes of lower body weight training/ twice per week (time depends on intensity). M-W
I usually rest on the weekends but occasionally go on walks or hikes.