Have you asked your uncle?
I am solo. My expenses were very little the first year. The next two years my gross increased and so did my costs. More income allows more equipment purchases to be made.
Had some jobs were extra man power was needed so some temp labor costs. Next year maybe no temp help costs.
Same with equipment. Say last year you bought the last thing you need. This year you make no equipment purchases. You may think your costs went down but you still have to set money aside so the money will be there when something has to be bought the next year.
Gas and oil?
You base hourly costs on working 40 hours. Though you may only have 20 hours work. Now you will be using half the fuel then you thought.
There are too many variables to come up with an accurate estimate. Just record your costs.
Also build in setting aside money to buy major equipment as a new truck.
Try to find out local pricing. Shoot for $60 an hour. Even if your costs are $10 hr and everyone else's is $30 do not drop your prices and leave money on the table.