Profit per mile is the single most important number in auto transport. It tells you whether each load you haul is actually building your business or quietly draining it. To calculate it, subtract your total cost per mile from your revenue per mile: if you earn $2.80/mile and your all-in cost is $2.10/mile, your profit per mile is $0.70. On a 1,000-mile run, that is $700 in your pocket — or nothing, if the math is wrong and you never checked.
Most owner-operators and small fleets in both the US and Canada track revenue reasonably well but dramatically undercount costs. Fuel gets logged; insurance, permits, and deadhead miles often do not. This guide walks through the full calculation, the most common leaks, and the levers you can pull to move the number in the right direction.
The Core Formula
Profit per mile = (Total revenue ÷ total miles) − (Total costs ÷ total miles)
Always use total miles — loaded and deadhead combined. A common mistake is dividing revenue by loaded miles only, which makes the number look better than it is. If you ran 1,200 miles to deliver a load but drove 300 miles empty to pick it up, your true distance is 1,500 miles.
Work this out monthly, not annually. Fuel prices, seasonal demand, and lane rates shift constantly. A quarterly average smooths over problems you need to catch in real time.
Full Cost Stack: What to Include
Operators consistently undercount costs by treating only fuel and driver pay as "real" expenses. Here is the full stack:
Variable Costs (per mile or per load)
- Fuel: Your biggest variable. At $4.00/gal (US) or ~$1.60/L (Canada), a car hauler averaging 6 mpg or roughly 2.5 L/100 km spends $0.67/mile or $0.064/km on fuel alone.
- Driver pay: Whether per mile, per load, or hourly — include all compensation, including bonuses and overtime.
- Tolls and permits: Oversize/overweight permits, highway tolls, and bridge fees. In Canada, provincial trip permits for oversize loads can run $50–$200 each depending on the province.
- Lumper and loading fees: Dealership or auction yard fees at pickup or delivery.
Fixed Costs (spread over miles)
- Insurance: Commercial auto, cargo, and liability. US fleets typically pay $12,000–$20,000/year per truck; Canadian fleets face similar ranges but premiums vary sharply by province and CVOR/NSC safety rating.
- Truck and trailer payments: Divide your monthly payment by average monthly miles. A $3,500/month payment on a truck averaging 8,000 miles/month adds $0.44/mile before you turn a wheel.
- Licensing and registration: US DOT operating authority, IFTA decals, IRP apportioned plates. In Canada: NSC carrier registration, CVOR certificate fees, and provincial licensing. Annual all-in cost for a single-truck US fleet typically runs $2,000–$4,000; Canadian fleets add GST/HST administration costs.
- Maintenance and tires: Budget $0.15–$0.25/mile as a baseline. Tires alone on an 18-wheel combination can cost $4,000–$6,000 per set.
- Depreciation: Your truck loses value every mile. Use IRS Section 179 (US) or CCA Class 10 (Canada/CRA) schedules as a proxy if you don't have another method.
- Overhead: Software, accounting, phone, office, and your own time if you're an owner-operator dispatching yourself.
Benchmarks: What Good Looks Like
Industry benchmarks vary by equipment type, lane density, and fleet size, but here are realistic targets for a standard 7–10 car open carrier:
| Metric | Thin (watch out) | Healthy | Strong |
|---|---|---|---|
| Revenue per mile | Under $2.50 | $2.75–$3.50 | $3.50+ |
| Cost per mile (all-in) | Over $2.40 | $1.80–$2.20 | Under $1.80 |
| Profit per mile | Under $0.30 | $0.55–$1.00 | $1.00+ |
| Deadhead ratio | Over 30% | 15–25% | Under 15% |
Canadian operators: convert to per-kilometre figures (÷ 1.609) and adjust revenue benchmarks for CAD — a healthy rate on a cross-border run will look different from a domestic Ontario-to-Alberta lane.
The Four Biggest Profit Leaks
1. Deadhead Miles
Every empty mile costs you roughly the same as a loaded one — fuel burns, the truck wears, and the driver's clock ticks. A fleet running 25% deadhead on routes that could support 15% is leaving significant margin on the table. Fix this by backfilling return lanes, using load boards strategically, or routing through secondary pickup points. Even dropping deadhead from 25% to 18% on a 10,000-mile month adds roughly $140–$200 back per truck.
2. Underpriced Loads
Many operators price by feel or by matching the last rate they saw on a board. If your cost per mile is $2.10 and you accept a load at $2.30, you made $0.20/mile — but one breakdown, one weather delay, or one re-inspection and you're negative. Know your floor before you quote, not after. Your floor is your cost per mile plus your minimum acceptable margin (most operators target at least $0.40–$0.60 above cost).
3. Maintenance Neglect Costs
Deferred oil changes, skipped brake inspections, and worn tires feel like savings. They are not. A roadside breakdown on a US interstate averages $800–$1,500 in towing and repair costs plus lost revenue for the downtime. In Canada, a failed CVOR inspection or roadside CVSA check resulting in an out-of-service order can ground a truck for days and flag your safety rating — which feeds back into insurance premiums.
4. Poor Invoice and Payment Tracking
Revenue you haven't collected is not revenue. Net-30 and net-60 broker terms are standard, but many operators carry 60–90 days of outstanding invoices without realizing it. Cash flow problems that feel like profitability problems are often collections problems. Tracking this in spreadsheets means it's easy for aging invoices to fall through the cracks.
How to Improve Profit Per Mile
Optimize Lane Selection
Not all lanes pay equally. High-density corridors — Toronto to Montreal, LA to Las Vegas, Texas triangle — typically support better rates because competition for loads is higher. Build a lane rate history for your top 10 routes so you know when a broker offer is below market. Reject loads that don't hit your floor; dispatch idle capacity to brokers or load boards rather than accepting unprofitable freight to "keep the truck moving."
Fuel Management
Fuel cards with network discounts (US: Comdata, EFS; Canada: Petro-Canada fleet cards) can save $0.03–$0.08/gallon or per-litre. On 8,000 miles/month at 6 mpg, that is roughly $40–$105/month per truck — small individually, significant across a fleet. Route planning that avoids unnecessary idling and aggressive braking also moves the needle; experienced drivers on efficient routes often beat estimates by 5–8%.
Load Density
An 8-car load at $300/car generates $2,400. A 6-car load at $350/car generates $2,100 with the same fuel and driver cost. Maximize car count per run where legally permitted and equipment allows. For enclosed carriers, understanding your weight limits (US: 80,000 lbs gross; Canadian provinces: 63,500–62,500 kg depending on axle configuration) is critical to staying legal while maximizing payload.
Software and Automation
Manually calculating profit per mile from QuickBooks exports, driver logs, and fuel receipts takes hours and introduces errors. Fleet management tools built for auto transport track cost and revenue per load automatically, flag underperforming lanes, and surface deadhead ratios in real time. The ROI of avoiding even one mispriced load per month typically exceeds the monthly software cost. See our pricing page to compare plans.
Regulatory Costs That Affect Your Margin
Compliance costs are real line items, not administrative noise:
- US (FMCSA/DOT): ELD mandate compliance, annual UCR registration ($69–$8,714 depending on fleet size), IFTA quarterly filings, and IRP renewals. A single FMCSA violation can trigger audits that cost far more than the fine itself.
- Canada (NSC/CVOR/CRA): NSC safety fitness certificates, CVOR abstract monitoring, provincial oversize permit fees, and CRA GST/HST remittances on taxable freight revenue. IFTA still applies to interjurisdictional carriers — see our IFTA guide for Canadian operators for filing specifics.
Budget 3–5% of gross revenue for compliance costs as a conservative estimate. Fleets that ignore this consistently underprice loads and then wonder why margins are thin.
Building a Monthly Profit Per Mile Dashboard
You don't need complex software to start — but you do need consistency. Track these five numbers every month:
- Total miles (loaded + deadhead)
- Total revenue collected (not invoiced — collected)
- Total variable costs (fuel, tolls, driver pay)
- Total fixed costs prorated for the month (insurance, payments, licensing)
- Deadhead percentage
From those five numbers you can calculate cost per mile, revenue per mile, profit per mile, and deadhead ratio — the four KPIs that tell you whether the business is healthy. Review them monthly, not at tax time. Problems caught at 30 days are fixable; problems caught at 12 months are crises.
If you're evaluating tools to help automate this tracking, our guide on choosing fleet management software for auto transport walks through what to look for. When you're ready to see these numbers in your own operation, start a free trial of AutoHauler AI — it connects to your load data and surfaces profit per mile, deadhead ratio, and lane performance automatically, so the math is always current and you can focus on running loads, not building spreadsheets.