Most contractors know what they spend on labor and materials for a job, but equipment costs get lumped into overhead and ignored. That hides the true cost of every project. The solution is calculating an internal equipment rate for each piece of equipment you own, then charging that rate to jobs based on actual usage hours.

The formula is straightforward. Add up annual depreciation, annual maintenance and repair costs, annual insurance, and estimated annual fuel for a given machine. Divide that total by the number of hours you expect to use it in a year. The result is your internal hourly rate for that piece of equipment.

For example, say you own a skid steer. Annual depreciation is $8,000 (purchase price minus salvage value divided by useful life in years). Maintenance runs $3,000 per year. Insurance is $1,200. Fuel averages $4,800 annually. That totals $17,000. If the machine runs about 1,000 hours per year, your internal rate is $17 per hour. Every job that uses the skid steer gets charged $17 for each hour it runs on that site.

Tracking hours is where most people fall short. Equipment logs are the simplest approach. Your operators or foremen record which machine worked on which job and for how long each day. A clipboard in the cab or a shared spreadsheet works. GPS and telematics systems automate this if you want more precision and less reliance on people writing things down. Either way, the data needs to get recorded daily. Waiting until the end of the week or month means guessing, and guesses aren’t useful for construction job costing.

Once you have equipment hours per job, the bookkeeping side is about entering those charges correctly. In QuickBooks, you can set up each piece of equipment as an item with its hourly rate and allocate costs to jobs the same way you allocate labor or materials. This gives you a complete picture of job profitability instead of a partial one that ignores the $200,000 excavator sitting on site for three weeks.

One useful exercise is comparing your internal rate against the local rental market rate. If your internal rate for a mini excavator works out to $45 per hour and you can rent the same machine for $35 per hour, owning it might not make financial sense unless utilization is higher than you estimated. On the flip side, if your rate comes in well below rental rates, that validates the purchase and shows you the real savings. This comparison also helps with bidding. You can price jobs using whichever rate is appropriate and know your margins are based on real numbers.

Fuel tracking deserves its own mention because it gets messy in construction. If you’re fueling equipment from a bulk tank on site, track gallons dispensed per machine. If operators are filling up at gas stations, receipts need to note which machine the fuel went into. Without this detail, fuel just becomes a general overhead expense and your equipment rates won’t reflect reality.

Review your internal rates at least once a year. Maintenance costs go up as equipment ages. Fuel prices fluctuate. Usage hours change as your project mix shifts. A rate you calculated two years ago might be significantly off today.

Getting equipment costs allocated to jobs is one of the biggest gaps in construction job costing in Phoenix. Contractors who close this gap consistently find that some jobs they thought were profitable actually weren’t, and that changes how they bid and what work they take on.