Calculators
Each one names its formula
Two trucking calculators disagreeing is usually two different assumptions rather than a mistake in either, and most sites will not tell you which they made. Each of these names the model it runs on the page, so you can check it against the source and know why another answer differs.
Cost per mile
Your real cost per mile from your own fixed costs and fuel economy, and the rate per loaded mile you must be paid to clear it once deadhead is taken out.
Fixed and variable cost accounting, split so the two behave differently
Lease-purchase break-even
How many miles a week a lease programme needs before it pays anything at all, and what it takes home at the miles you are actually offered.
The same cost model, applied to a weekly fixed obligation
Federal bridge formula
Maximum legal weight on an axle group by count and spacing, which is why a truck under 80,000 pounds gross can still be over on a group.
23 U.S.C. 127, W = 500 x ( (L x N) / (N - 1) + 12N + 36 )
Diesel by region
This week's price in every PADD region, what each one costs per mile at your economy, and what a fuel surcharge over a pegged base should be paying.
EIA weekly retail on-highway prices, refreshed from the published source