We always figured the cost of operation thus:
Total Purchase cost (this would include finance charges)/low average hour lifespan of the machine. This would give us our static rate for the machine and we would use it for every job.
Then maint cost:
X cost per 200 hours/200 (oil, filters, fluids)
Y cost per 2,000 hours/2000 (tires, tracks, etc)
We would then add in fuel cost
fuel burn rate * fuel cost
Then operator wage and benefits.
We estimated the insurance and transport into the bottom of the bid, we did not assign them in the hourly rate, so you may want to add them into the cost.
See if I can make this look right.
Dozer A static cost.
$100,000 sticker + $10,000 interest = $110,000
Dozer A's Low average commercial lifespan is 9,000 hours.
$110,000/9,000=$12.25 Static Cost. This number never changes.
Dozer A: Maint
$750 per 200 hr (or what ever interval is used) GOF
$750/200hr = $3.75/hr
$5,000 per 2k hours for new tires or under carriage work.
$5,000/2k hr= $2.50/hr
Dozer A: Fuel Cost. This is the one that requires a very close eye, screw up on this and it will hurt you.
4 gallons per hour @ $3 a gallon = $12
Static cost: $12.25
Basic Mtnc :$ 3.75
Wear Mtnc :$ 2.50
Fuel Cost :$12.00
Machine :$30.50/hr
This is what it costs to turn the (hypothetical) machine on and use it in a manner that doesn't cause breakage. Now you haven't paid for your time, the insurance, or gotten any ROI using this.