Stand at a hole with the pile beside it. Same dirt, and the pile is obviously bigger than the hole. Everyone in this trade knows that, and a surprising number of people never price it.
Bank yards, loose yards and compacted yards are three different numbers describing one job. The gap between them has to live somewhere, and when it is not in the bid it lives in the contractor's pocket, quietly, for the whole job.
Three Yards, One Job
Bank yards are what is in the ground before anybody touches it. That is what your takeoff off the plans gives you, and it is the only one of the three most people ever calculate.
Loose yards are what is on the pile and in the truck. The ground comes apart when you dig it, so the same material occupies more space out of the hole than it did in it. Haul is priced on this number, not the first one.
Compacted yards are what the material occupies once it is placed and compacted back down. That is less than loose, and often less than bank.
Bid one of those and haul another and you are eating the difference across the whole job, on every single load.
Swell Is What the Truck Sees
If your load count is built off bank yards, you are short of trucks before the first one leaves the site. That does not usually show up as a dramatic failure. It shows up as a schedule that slips, a second day of trucking nobody priced, and a driver you did not plan on paying.
The fix is boring and it works: count real loads on your own jobs, in your own ground, and build your own factor. That is a number you own, and nobody can sell it to you.
Shrink Is What the Fill Sees
Put material back and compact it and it takes up less room than it did loose, and frequently less than it did in the bank. So the import you were sure you did not need turns up as a bill in week two, on a job where you have already handed somebody a number.
On a balanced site that assumption is the whole bid. If the cut is supposed to fill the fill and it comes up short, every yard of the shortfall is bought, hauled and placed at your expense unless you wrote the assumption into the contract.
Clay, Sand and Rock Do Not Behave the Same
Use a rule of thumb for your own dirt, and say out loud that it is a rule of thumb rather than a fact. What ground does in Jefferson County, Missouri is not what it does in east Texas or in northern Ohio.
This is the honest limit of any estimating education, and it is worth stating plainly rather than papering over. Rates and soil are local. The method is not. Swell and shrink, machine cost per hour, overhead recovery and the clauses in a subcontract behave the same way in every state. The percentages you feed them do not, and any course, book or program that hands you a single national swell factor is handing you a false certainty.
Why the Software Will Be Confidently Wrong
A review sweep of this entire category found fifteen of fifteen results were software. There is no reviewed education product in excavation estimating at all, and on page one of the organic results for excavation estimating there is not one credentialed practitioner.
That tells you what the market has decided you need. It has decided you need a faster calculator.
A program will give you a number to two decimal places and it will be wrong, because it does not know what your dirt does. You have to know what your dirt does. The arithmetic was never the hard part. A book cannot look at your bid and tell you the number is wrong, and software is worse in one specific way: it returns a confident figure whatever you feed it.
You are not short of formulas. You are short of judgement about what to put in them.
The Arithmetic, With Round Numbers
This is arithmetic rather than a job. No Checkered Flag figures are in it, and the percentages below are illustrative, not a recommendation for your ground.
Say the takeoff says a thousand bank yards coming out. You price the haul off that thousand, at whatever your truck costs per load, and you build a schedule around the number of loads that implies.
Now the material swells on the way out of the hole. Whatever your factor is for that ground, the pile is bigger than the hole was, and the trucks are hauling the pile, not the hole. Every percentage point of swell you did not price is a percentage point more loads, more driver hours and more tipping, and none of it is recoverable on a lump sum.
Then look at the fill side of the same job. If that material is going back in and getting compacted, it occupies less than it did loose and frequently less than it did in the bank. If the job was sold as balanced, the shortfall is bought, hauled and placed at your expense.
Neither of those is a dramatic error. Nobody stands on site and says the yardage was wrong. It shows up as a schedule that slipped, a second day of trucking, and a month that came in flatter than it should have. That is why it goes uncorrected for years at a time.
The correction is not clever. Count loads on your own jobs, in your own dirt, until you have a factor you trust. Then write the assumption on the bid so the ground has to argue with a document instead of with you.
Where This Actually Bites
It is never the big obvious thing. It is one line you were light on, and you do not find it until the machine is loaded and you are going home.
Two practical habits catch most of it. First, check the yardage twice on any job where the dump is a long way out, because on those jobs the haul is a bigger share of the bid than the digging. Second, write the assumption down: state on the bid what you assumed about swell, about balance and about import, so that when the ground disagrees with you there is a document rather than an argument.
That second habit is worth more than it looks. The priced scope and the actual dirt turning out to be two different jobs is one of the most common complaints in this entire trade, and a written assumption is the cheapest protection against it that exists.
Frequently Asked Questions
What is the difference between bank, loose and compacted yards?
Bank is what is in the ground. Loose is what is on the pile and in the truck, which is more. Compacted is what it occupies once placed and compacted, which is less. One job, three numbers, and haul is priced on the loose one.
How much does soil swell when excavated?
It depends on the material and on your ground. Build a factor from your own load counts, call it a rule of thumb rather than a fact, and check it on your own jobs.
Will takeoff software get swell and shrink right for me?
It will give you a number to two decimal places and it will be wrong, because it does not know what your dirt does. The factor you feed it is the hard part, and that comes from your ground.
Two Ways to Use This
If you run your own machine, anywhere in the country, the free Bid Worksheet on this site is a blank one-page structure for pricing a dirt job, from scope to the final number. It is free, it takes one step to get, and there is no call to book and no sales page in the middle of it.
If you are a homeowner, a builder or a general contractor in Jefferson County or the greater St. Louis metro and you would rather somebody who has been doing this since 1998 worked the number out for you, that is the day job. Checkered Flag Excavation, De Soto and Festus, Missouri. Call 636-586-1794.
Jay Voisey owns Checkered Flag Excavation, Inc., founded 1998, with locations in De Soto and Festus, Missouri. He is a licensed septic installer and septic inspector, a St. Louis County licensed Master Drainlayer, an approved St. Louis County land disturbance special inspector,. Checkered Flag is WBE certified and holds a BuildZoom score of 92, the top third of 23,328 licensed Missouri contractors.