If you've ever sold a 3D printed part for "10 bucks because that's what it felt like", this article is for you. The real cost of a printed part is almost never what makers guess. After running a 3D printing shop for two years and helping hundreds of others through 3DPartCalc, I've seen the same five mistakes repeat — and the same five fixes solve them.
This guide walks through the full cost stack of a single 3D printed part with real numbers from real machines: a Bambu Lab A1 and a Prusa MK4S, both running PLA at 2026 prices. By the end you'll know exactly which line items to track, the typical share of total cost each one takes, and the specific overhead percentages that turn a "looks profitable" job into one that actually pays your power bill.
The five costs every printed part has
Anyone selling 3D printed parts should be tracking at least these five inputs:
- Material — the filament burned, including waste from purges, brims and skirts.
- Electricity — what your wall socket actually delivers across the print, not the nameplate watts on the printer's box.
- Machine amortization — the slice of your printer's purchase price + maintenance you "spent" on this print.
- Labor — slicing, post-processing, packing, customer comms. The line most makers underprice or skip entirely.
- Hardware + packaging + logistics — screws, magnets, inserts, the box, the bubble wrap, the courier pickup fee.
Plus one multiplier on top: a failure rate. Because some prints fail and you ate the cost. Skipping this is the single biggest reason "profitable" jobs end up underwater.
1. Material cost: more than just grams × $/kg
A 42 g PLA part using $20/kg filament costs (42 / 1000) × 20 = $0.84 in raw material. That's the easy part. The real cost is higher because of:
- Purge towers and brims: typically 1-3 g per print. On multi-color jobs (AMS, MMU), purges can dominate — sometimes 30-50% of total filament for a small two-color part.
- Slicer overhead: the slicer's "filament used" estimate is the optimistic case. Real-world consumption is 3-5% higher because of underextrusion compensation, support skirts, and the inevitable failed first layer that you don't always count.
- Spool waste: the last 10-30 g of every spool that's too tangled or too short to use reliably. If you toss it, count it as material cost spread across the spool.
3DPartCalc handles this with a "material efficiency" setting, default 95%. So a 42 g job at $20/kg actually costs (42 / 0.95) / 1000 × 20 = $0.88. Small per-part, but on 1000 prints/month that's $40 you weren't tracking.
2. Electricity: stop using nameplate watts
This is where most calculators lie. The Bambu Lab X1 Carbon's nameplate is 1000 W (you can read it on the box). The actual average draw during a 2-hour PLA print is closer to 180 W. Why?
- The 1000 W spike happens for ~30 seconds while the heated bed warms up, then never again.
- The hotend cycles at ~50 W average once at temperature.
- Steppers, fans and the motherboard add another ~30-40 W steady-state.
If you bill electricity using nameplate, you're 5-6x over-charging customers. If you bill using "what I felt like", you're under-recovering. Either way, you don't know your margin.
3DPartCalc ships with measured average power draw for 37+ printers (kill-a-watt data + community forum threads cross-checked). Pick yours from the dropdown and it auto-fills. For a Bambu A1 at 100 W avg, a 1.5-hour print at $0.15/kWh costs:
1.5 hours × 100 W × $0.15/kWh × 1.1 buffer
= 0.0248 USD
Two and a half cents. That's it. Electricity is rarely the dominant cost — but it's the one most people get wrong by an order of magnitude in both directions.
See the per-printer breakdowns: Bambu A1, X1 Carbon, Prusa MK4S, Creality K1.
3. Machine amortization: the line nobody wants to count
Your printer is a fixed cost spread across every print it does in its lifetime. A Bambu A1 costs $399 and will reasonably last ~10,000 hours of printing before something major breaks (extruder, mainboard, or you get bored and upgrade). That works out to roughly 4 cents per print-hour just to amortize the hardware:
$399 / 10,000 hours = $0.0399/hour
Plus maintenance: belts, nozzles, build plates, hotend rebuilds. Budget $40-60/year for a hobby printer that's running daily. That's another ~1 cent per print-hour. Total amortization for a 1.5-hour print on a Bambu A1: about $0.075.
For a Prusa XL at $2,500 with similar lifespan, the same 1.5-hour print eats ~$0.46 in amortization — six times more. This is where the "expensive printer with cheap material" pricing model breaks down: the machine itself is not free.
4. Labor: the cost most makers refuse to count
"But I would have been on the couch anyway, the time was free." No, it wasn't. Slicing, slicing fixes when the first attempt fails, file conversions, customer back-and-forth on dimensions, post-processing (deburring, supports removal, sanding), QC photos, packing, label printing, dropoff at the courier — pick a number and it's probably 15-20 minutes per order minimum, even for a single part.
If your time is worth $15/hour (low side for a skilled trade), 20 minutes of labor = $5 per order. That's a cost. Hide it and your "profit margin" is fiction.
3DPartCalc's default labor rate is $15/hour with 0 minutes per part — you tune both based on your reality. For commission work where you're physically present (e.g., resin curing or post-processing detail), labor often dominates the entire cost stack.
5. Hardware, packaging, logistics
The line that scales fastest with order complexity. Some real numbers from running a small shop:
- Threaded inserts (M3 brass): $0.04 each.
- Magnets (10 mm × 2 mm N52): $0.12 each.
- Padded mailer (small, with logo): $0.40.
- Bubble wrap + tape: $0.08 per box.
- Courier pickup (Argentina, OCA): about $2.50 amortized across one to four orders.
For a typical printed-and-shipped order of 1-3 small parts, hardware + packaging + logistics commonly hits $3.50 to $5.00. Bigger than the material cost. Bigger than the electricity cost. Often bigger than the machine amortization. Track it.
The failure rate multiplier (the one that gets you)
Some prints fail. Bed adhesion, layer shift, clogged nozzle, power outage, the cat. Across 12 months of production printing on Bambu and Prusa hardware, my measured failure rate sits at 4-7%, depending on material and complexity. PLA on a Bambu A1 with auto-bed-leveling: closer to 2%. PETG-CF on a Prusa MK4S with a complex multi-part bed: 8-10%.
When a print fails, you've still spent the material, the electricity, the machine hours, and possibly some labor. So your real production cost per successful part is:
real_cost = production_cost × (1 + failure_rate)
A 5% failure rate adds 5% to every part's cost. If your "profit margin" is 30% and you forgot the failure multiplier, your real margin is closer to 23%. On a 5-buck part, that's $0.35 less profit you didn't budget for.
Putting it all together: a worked example
Let's price one part: 42 g PLA, 1.5-hour print, on a Bambu Lab A1, with $0.15/kWh electricity and a 5% failure rate. Standard small order: 2 magnets, mailer, courier share. 15 minutes of labor at $15/hour.
| Line | Cost (USD) | % of total |
|---|
| Material (42 g / 0.95 × $20/kg) | $0.88 | 9% |
| Electricity (1.5 h × 100 W × $0.15/kWh × 1.1) | $0.025 | 0.3% |
| Machine amortization ($399/10000 h × 1.5) | $0.06 | 0.6% |
| Labor (15 min × $15/h) | $3.75 | 40% |
| Hardware (2 × $0.12 magnets) | $0.24 | 2.5% |
| Packaging + logistics share | $3.05 | 32% |
| Production subtotal | $8.00 | 84% |
| Failure rate (×1.05) | $0.40 | 4% |
| Real cost | $8.40 | 88% |
| Profit margin (×1.40) | $3.36 | 35% |
| Suggested price | $11.76 | 123% |
Note where the cost actually lives. Material is 9%. Labor and packaging are 72%. Most makers obsess over filament price ("the cheap PLA versus the premium PLA") and ignore the lines that actually move the needle.
The five mistakes that cost money
- Using nameplate watts. Always use measured average draw. Off by 5-10x otherwise.
- Skipping labor. Even hobby work has labor. If you don't bill it, you're paying yourself sub-minimum wage.
- Forgetting the failure rate. 5% sounds tiny, but it's 5% off your entire cost base, every order.
- Eyeballing packaging. Mailer + bubble wrap + courier amortization adds up to more than your filament cost on small orders.
- Using percentage margin without a per-order minimum. A 30% margin on a $4 cost is $1.20 of profit, which doesn't cover the time you spent answering the customer's "is this PLA or PETG?" email.
Stop guessing
You don't need a spreadsheet for this. 3DPartCalc runs the full math live in your browser, no signup required, with realistic defaults pre-loaded for 37 popular printer models. Punch in your part's grams and print time, pick your printer from the dropdown, and you'll see the breakdown above filled in with your numbers.
If you're running a Bambu A1, jump straight to the Bambu A1 cost calculator. Other popular pages: Bambu P1S, Bambu X1 Carbon, Prusa MK4S, Creality K1, Anycubic Kobra 2 Pro.
Save the SKU after you compute it and the next time the same customer orders the same part, you'll have the price ready in two seconds. That alone pays for the 90 seconds it takes to set up the calculator the first time.