Some carriers are taught to think in cost per mile. It’s familiar. It’s easy to explain. And it’s only part of the picture. Cost per mile tells you how expensive it is to move the truck down the road. It does not tell you how expensive it is to run a business. That’s where cost per hour and cost per day come in.
If you operate in the spot market, especially off load boards, these two numbers often matter more sometimes than cost per mile. They explain why some “good-paying” loads still leave you confused at the end of the week, and why certain cheap-looking loads quietly keep you profitable.
This article will walk through:
- How to calculate cost per hour
- How to calculate cost per day
- How these tie back to breakeven and operating ratio
- Why these numbers change how you look at load boards
- Practical spot-market examples you can use immediately
Breakeven Still Comes First
Before we talk hourly or daily costs, we have to anchor this to something solid. Every carrier has two buckets of expenses:
Fixed Costs
These exist whether the truck moves or not:
- Truck payment
- Insurance
- Permits and compliance
- Trailer payment
- Accounting, ELD, subscriptions
- Your base salary draw (yes, this counts)
Variable Costs
These scale with usage:
- Fuel
- Maintenance and repairs
- Tires
- Tolls
- DEF
- Driver pay (if applicable)
Your breakeven answers one question:
“What does it cost me to keep the doors open before I make a dollar of profit?”
We cover this in depth in the breakeven and operating ratio lessons, but here’s the key reminder:
- Breakeven isn’t just a mile number
- It’s a time number too
Why Cost Per Mile Falls Short in the Spot Market
Cost per mile assumes movement and is calculated to represent the associated costs with the turning of wheels.
Load boards then introduce:
- Detention
- Live loads and unloads
- Deadhead
- Traffic
- Weather
- Appointment windows
- Broker delays
Two loads can pay the same rate per mile and produce very different outcomes depending on time.
That’s why experienced spot carriers stop solely thinking:
“What’s the rate per mile?”
And start considering:
“How long is this going to take?”
Step One: Calculate Your Cost Per Day
Cost per day is one of the simplest and most overlooked KPI in trucking.
Formula:
Monthly Fixed Costs ÷ Operating Days Per Month = Cost Per Day
Example:
- Monthly fixed costs: $12,000
- Operating days: 22
$12,000 ÷ 22 = $545 per day
That means:
- Every day the truck operates must cover at least $545
- Before fuel
- Before maintenance
- Before profit
This number doesn’t care if you ran 600 miles or 60 miles. It only cares that the day existed.
Step Two: Calculate Your Cost Per Hour
Now we convert time into money.
Formula:
Cost Per Day ÷ Average Working Hours Per Day = Cost Per Hour
Let’s continue the example:
- Cost per day: $545
- Average workday: 11 hours (driving + waiting + loading)
$545 ÷ 11 = $49.55 per hour
That’s your fixed-cost burn rate. Every hour the truck is “on the clock,” it’s costing you roughly $50 before variable expenses.
This is where the light bulb usually comes on.
Add Variable Costs to the Hourly Equation
Now layer in variable costs.
Let’s say:
- Fuel + maintenance average: $0.75 per mile
- Average speed (including slowdowns): 50 mph
That’s: $37.50 per hour in variable costs
Now combine them:
- Fixed cost per hour: $49.55
- Variable cost per hour: $37.50
Total cost per hour: $87.05
This is your true operating cost per hour. A real number.
Why This Changes How You Read Load Boards
Let’s look at two spot loads.
Load A
- 500 miles
- $2.10/mile
- Total revenue: $1,050
- Transit + wait time: 14 hours
Hourly revenue:
$1,050 ÷ 14 = $75/hour
Your cost per hour:
$87/hour
Result: You ran a “decent” rate and still lost money.
Load B
- 320 miles
- $1.85/mile
- Total revenue: $592
- Transit + wait time: 7 hours
Hourly revenue:
$592 ÷ 7 = $84.50/hour
Still not great — but now you’re close. Add a quick reload or a short deadhead run and this day can turn profitable.
This is why experienced spot carriers will sometimes take:
- Shorter runs
- Lower RPM
- Faster turns
Time efficiency beats mileage optics.
Cost Per Day Helps You Decide When to Shut It Down
Another advantage of cost per day: it helps you know when not to run.
If your cost per day is $545 and:
- The only load available pays $400
- Takes the full day
- Creates wear and tear
You’re better off:
- Parking
- Resetting
- Waiting for a better opportunity
Running just to stay busy is often more expensive than sitting.
How This Ties Back to Operating Ratio
Operating ratio measures:
Expenses ÷ Revenue
Cost per hour and cost per day help you control the expense side.
When you understand:
- How fast money leaks per hour
- How much each day must produce
You stop chasing gross revenue and start protecting margin. This is how small carriers survive long downcycles while others burn out.
The Big Shift in Thinking
Cost per mile answers:
“Can I move freight profitably?”
Cost per hour answers:
“Am I using my time wisely?”
Cost per day answers:
“Should I even be running today?”
Spot carriers who master all three stop guessing and start deciding.
Final Thought
The spot market doesn’t reward optimism. It rewards awareness and if you don’t know what every hour costs you, the load board will decide for you.
