Free tool to check which of your past jobs actually made money. Load completed jobs with real material, labor, machine, and overhead costs, and see which customers are quietly draining your bottom line.
| Job | Customer | Revenue | Material | Outside | Lbr hrs | Mach hrs | Profit | |
|---|---|---|---|---|---|---|---|---|
| $2,036 | ||||||||
| $234 | ||||||||
| $3,330 | ||||||||
| $14 | ||||||||
| $1,140 |
Every shop owner has a gut feeling about which customers are profitable and which ones aren't. The gut is usually wrong. Not because shop owners are bad at their business. They're not. The jobs that feel profitable are the ones that run clean and ship on time. The jobs that actually make money often look annoying on paper. And the jobs that lose money usually look fine right up until you load all the real costs into them.
This calculator is a retrospective job costing tool. You drop in a list of completed jobs, customer, revenue, material cost, labor hours, machine hours, and it loads the real cost of running those jobs at your shop rate. You see margin per job, a weighted customer rollup, and how much money you'd put back on the bottom line by dropping your worst performers. Nothing here is forward-looking quoting math. This is retrospective, did-I-actually-make-money math.
Paperless Parts has cited that 10 to 20 percent of the jobs in a typical small shop are unprofitable, and the shop doesn't know it. ProShop ERP puts the number higher. The reason isn't laziness. It's that tracking cost at the job level takes a discipline most shops don't have, because it never feels urgent. You quote a job, you run it, it ships, you invoice, the check clears. As long as enough checks clear each month the shop stays open. Nobody goes back and asks whether that specific job, with those specific setup hours and that specific scrap rate, actually made the margin you quoted.
The jobs that quietly drain money tend to share patterns. Long setups for small quantities. Customers who request small changes mid-run. Materials you don't normally stock, so you pay a premium at the distributor. Customers who always want it expedited. None of those things are fatal on their own. Loaded into the same job at the same time they're the difference between a 22 percent margin and a negative 8 percent margin.
A proper retrospective job cost has six components. Material (what you actually paid your supplier, not what you estimated). Outside operations (heat treat, plating, coating, anything you sub out). Labor hours times loaded labor rate (wage times burden, not just wage). Machine hours times machine hour rate (depreciation plus power plus tooling plus repairs). Overhead allocation (rent, insurance, admin, divided by total running hours). And scrap or rework if any. Skip any of those and your cost number is low, which means your margin looks higher than reality.
The machine rate and overhead allocation are where most shops cut corners. "I figure about $30/hour total" is a typical answer. That number is almost always wrong. Usually too low. A real machine hour rate on a modest VMC, properly computed, runs $45 to $70 an hour once you load depreciation, power, tooling, repairs, and the overhead share. If you've already done the shop rate math you have these numbers. If you haven't, do that first. Plug the outputs into this tool and you'll see a different picture than the one in your head.
Averaging job margins gives you a misleading answer. Say you have ten jobs at 25 percent margin and one job at negative 40 percent. The simple average is (25 times 10 minus 40) divided by 11, which comes out around 19 percent. Sounds fine. But if the losing job is $20,000 in revenue and the ten winners average $1,500 each, the actual weighted margin for that customer is negative. A single large loser hides behind a pile of small winners if you don't weight by revenue.
This calculator uses revenue weighted margins for every customer rollup. It's the only honest way to see customer level profitability. If a customer shows up at the top of the loser list, the question isn't "are those jobs bad". The question is "why is the total margin on this relationship negative even though some wins are mixed in". That usually leads to a pricing conversation, a process change, or sometimes a clean break.
Once you run the analysis, the calculator shows you how much money you'd add per month by simply not taking the three worst jobs on the list. That number is often startling. $800, $1,200, $2,000 a month in money you're currently losing on work you're actively doing. It's the fastest positive change a shop can make. No new customer required. No equipment to buy. You just say no to three quotes you would have said yes to last quarter.
Saying no is hard when you're used to running hot, so a number helps. If you can see on paper that dropping three specific customers would add $1,200 a month to profit, that's $14,400 a year in found money. You still need the shop full, but now you know which jobs to replace and the price floor to replace them at.
Start with the last 30 days of completed jobs. Pull them from your board, your invoicing tool, or a handwritten list. For each job you need six numbers: job ID, customer name, revenue (what you invoiced), material cost (what you actually paid), labor hours logged, and machine hours run. If you track outside operations separately, add those. If you don't, fold them into material cost.
Set your rates at the top. Loaded labor rate, machine hour rate, and overhead per hour. If you don't know these cold, use 1.23 times your machinist's wage for loaded labor, $35/hour as a rough machine rate on a modest VMC, and $15/hour for overhead. Those are conservative starting numbers. Real shops usually come in higher. You can refine them as you go.
Paste your jobs into the table or add them one at a time. The calculator highlights losing jobs in red and rolls everything up by customer. Export a PDF when you're done. It's formatted clean enough to hand to your accountant or keep as a monthly record. Nothing gets sent to a server. The whole calculation runs in your browser and your numbers stay local.
Free tool from swarf.shop. No email, no signup, no catch. We build job tracking software for small machine shops — these calculators are stuff we needed ourselves.