Just factor 3.5 hours for your preload pay x 5 days a week for 52 weeks. Now account for a few call outs (let's say 3 to 5 for example) for things you didn't plan on happening. Don't factor in your raise either. Depending on your location, add in your peak driving with an average of 8 hours per day, although it should be more. Don't add anything in for driving throughout the rest of the year because that's super spotty. This should give you a base line to start with. I screwed up last year and didn't plan it out right, now I'm sitting on next to no money because of having to evacuate for Irma and having monthly bills pile up, although I've made $41,000 as a preload/TCD.
Things I'm going to definitely be doing next year include buying out my insurance plan from day 1 instead of making 12 payments. This will free up the $160 a month. Also going to set aside 6 months of car payments so I don't have to worry about my car from April - October as well as an extra $100 per month for those 6 months as well. Also, this doesn't factor in my tax return, so we'll use that for needs that we haven't addressed so far this year (new washer/dryer, fix cars, etc). Add in as much money in savings as you can for leisure and that's about as base line as I can get it..
