How to calculate profit margins on custom jobs (without a spreadsheet)

Ask most shop owners what their margin is on a typical job, and you'll get one of two answers: a confident number that's probably wrong, or an honest "I don't really know."

Custom work is hard to price. Every job is different. Materials vary. Labor hours are unpredictable. And by the time you're done, you've forgotten what you originally estimated.

But here's the thing: if you don't know your margins, you can't know if you're actually making money. You might be busy and broke at the same time.

The basic margin formula

Let's start with the fundamentals. Profit margin is the percentage of revenue that's left after you subtract your costs.

If you charge $1,000 for a job and your costs are $600, your margin is:

($1,000 - $600) ÷ $1,000 × 100 = 40% margin

Simple enough. The hard part isn't the math. It's knowing your actual costs.

What goes into job cost?

Most shops dramatically undercount their costs. Here's what you should be including:

Direct materials

This is the obvious one. Raw materials, components, hardware, consumables. But are you using current costs or the price you paid six months ago? Material prices change. Your margins should reflect what you're actually paying today.

Labor

Not just wages, the fully loaded cost including payroll taxes, benefits, and workers comp. A $25/hour employee probably costs you $32-35/hour when you add everything up.

Machine time

Your equipment costs money whether it's running or not. Depreciation, maintenance, tooling, electricity. If you're not accounting for machine time, you're subsidizing your customers.

Setup and programming

The time before chips fly counts too. Fixture setup, CAM programming, first article inspection. These hours are real costs that need to be in your price.

Overhead allocation

Rent, utilities, insurance, office staff, your own salary. These costs exist whether you're working or not, and every job needs to carry its share.

Why spreadsheets fail at job costing

Most shops try to track margins in spreadsheets. It sort of works, but it creates problems:

Stale data

Your spreadsheet has material costs from when you last updated it. Meanwhile, your supplier raised prices twice. You're quoting with old numbers and wondering why jobs feel tight.

No integration

Your quote lives in one spreadsheet. Your material costs in another. Your labor tracking somewhere else. To calculate actual margin, you have to pull data from three places and hope nothing got mistyped.

After-the-fact analysis

With spreadsheets, you usually calculate margin after the job is done. By then it's too late. You needed to know the margin before you sent the quote, not after you finished the work.

Too much friction

If calculating margin is hard, you won't do it for every quote. You'll do it for big jobs and guess on the small ones. Those small jobs add up.

How to get real-time margin visibility

The shops that actually know their margins have systems where cost data flows automatically. Here's what that looks like:

1. Maintain current material costs

Your inventory system should track what you paid for materials, not what you paid last year. When you receive stock, update the cost. When you add an item to a quote, use the current cost automatically.

2. Build margin into your quote builder

Every line item should show cost, price, and margin. As you build a quote, you should see the total margin update in real time. No separate spreadsheet required.

3. Set margin targets

Know your minimum acceptable margin. If you need 35% to cover overhead and make a profit, you should see a warning when a quote dips below that. Catch thin margins before you send, not after you deliver.

4. Track quoted vs. actual

After jobs complete, compare what you quoted to what you actually spent. This feedback loop helps you quote more accurately over time.

Markup vs. margin: know the difference

These terms get confused constantly, but they're not the same:

Markup is how much you add to your cost to get your price.
Margin is what percentage of the price is profit.

Example: You buy material for $100 and sell it for $150.

• Markup: 50% (you added $50 to your $100 cost)
• Margin: 33% ($50 profit ÷ $150 price)

If you want a 40% margin, you need a 67% markup. If you want a 50% margin, you need a 100% markup. The math matters, and getting it wrong means pricing yourself into losses.

What good margins look like

Healthy margins vary by industry and job type, but here are some benchmarks:

• Materials only (resale): 25-40% margin
• Standard fabrication: 35-50% margin
• Complex custom work: 40-60% margin
• Rush jobs: 50%+ margin (you're selling speed)

If your margins are consistently below these ranges, either your costs are higher than you think, or you're underpricing. Both are fixable once you can see the numbers clearly.

The margin visibility payoff

When you can see margins in real time, everything changes:

• You price with confidence: No more guessing. You know exactly what you need to charge.
• You catch bad jobs early: That "favor" for a good customer? Now you can see exactly how much that favor costs.
• You negotiate better: When a customer pushes for a discount, you know exactly how low you can go.
• You identify winners: Some job types are more profitable than others. Margin data shows you where to focus.

Stop guessing at margins. Stop hoping jobs are profitable. Get the visibility you need to price with confidence and grow a business that actually makes money.

Ready to see your real margins? Schedule a demo of AirShop.