The way we plan our journeys is to plan our route in Google Maps. Google Maps will tell you the distance you will need to travel and how many hours it will take.
We like to drive around 4 hours per day, which usually allows us enough time to stop and take pictures, picnic, or do whatever we decide to do along the way. If Google maps says that a trip will take us 28 hours to complete, we then have 7 days to journey at least. If we decide to spend an additional day in one place, we just add it to our days of travel.
We also have a fairly simple way of calculating our expenses. Gas for driving 4 hours = $35.00.
For hotel stays, we budget $125.00 per night with breakfast included, (we can usually find cheaper, but this is an estimate).
Food along the way: We usually try to stay at a hotel that has breakfast included, even a continental type breakfast. Breakfast included saves us $40.00 per day.
We estimate $20.00 for lunch which usually includes a homemade sandwich or other picnic type food. We have one of those insulated bags with an ice pack for our picnic food. I usually try to keep some buns, salad dressing, deli meat, cheese, 2 red peppers, carrots, and granola bars as staples in our picnic pack. We also buy a box of bottled water when traveling for a few days or more.
Supper is the big one at $60.00 per day. We do mix our general estimates up when we travel, we may not go to a restaurant for supper, or we may have a larger lunch and smaller supper or buy a pizza at the hotel room, etc.
Eating every meal out is expensive and you get tired of restaurant food in a big hurry on the road. It also casts time, at least an hour for each meal. That is often time that we would like to spend doing something else like visiting a site of interest.
Total daily food is estimated at $120.00 per day, but because breakfast is usually included, the real cost estimate is $80.00 per day. Often it is even cheaper as we prepare meals in the hotel room or picnic areas we stop at.
Our daily estimated expenses run $35.00 (gas) + $125.00 (hotel) + $80.00 (food) = $240.00 per day budgeted, but it always comes out less for us. $240.00 is a generous working budget number where we know we can plan confidently.
Our 7 day trip will cost us 7 X $240.00 = $1680.00. As I say, we pretty well always overestimate, but this is how we make the travel budget.
Using 4 hours per day for driving and expenses of $240.00 per day is the basis of our trip planning.
We do not order alcohol with dine-in meals, but usually have a bottle of wine or a few cans of beer traveling with us that we might consume in the hotel room/patio/balcony afterward.
Everything can be varied, but this is our general way of planning our travel.