The true cost of a 3D print, per good part
A print’s cost is not its filament. It is filament, the machine hours the print occupies, the electricity those hours draw, the share of prints that fail and must be paid for twice, the finishing each part needs, and the setup spread across the batch. This page builds all of it at your figures: material by weight at your price per kilogram, machine time at your hourly machine rate, power from the printer’s wattage and your electricity price, failures grossed up properly (a 15% failure rate means printing 100 good parts takes about 118 attempts’ worth of cost), post-processing per part, and setup per batch. The headline figures are the batch total and the cost per good part.
The batch and the material
Machine time and power
Failures, finishing and setup
Disclaimer: This calculator gives estimates for general information only. It is not financial, medical or other professional advice. Printed parts for load-bearing, pressure, food-contact or safety uses need appropriate materials, testing and qualifications that a cost estimate cannot provide.
What this calculator does
It costs a batch of 3D printed parts the way a print business has to: from the slicer’s two honest numbers, grams and hours, outward to everything those numbers drag with them. Material is grams times price per kilogram, supports included, because waste plastic was purchased plastic. Machine time is charged at an hourly rate that carries depreciation and wear, since a printer printing your part is a printer ageing. Electricity is computed from wattage, hours and tariff rather than waved away; it is small, and it is shown anyway, because a costing that omits small real costs teaches the habit of omitting larger ones. Failures are handled by the correct arithmetic, division by the success rate, applied to print costs only, and finishing and setup stand where they belong, per part and per batch. The outputs are the batch total and the figure every quote and make-or-buy decision needs: the cost per good part.
How to use it
- Take grams and hours from the slicer, supports switched on. The slicer’s estimate with your actual profile (infill, walls, supports, brim) is the closest thing to a measurement this process has before printing. Costing from the bare model’s volume understates material by the supports and understates time by every travel move you forgot.
- The machine rate is depreciation wearing overalls. A printer’s price divided by its realistic service hours, plus maintenance, nozzles, beds and belts, gives an hourly figure that keeps replacement funded. At zero machine rate every print looks profitable and the printer’s replacement arrives as an unbudgeted catastrophe; the field exists to prevent that specific illusion.
- Failure rate from memory is always too low. Count failed prints over a real stretch, including the ones abandoned mid-job and the first layers that never became prints. The grossing-up arithmetic is unforgiving in the right way: at 25% failures the print costs divide by 0.75, and a part’s print cost rises by a third, which is simply what a one-in-four failure habit costs.
- Price your finishing time or admit it is free. Support removal, sanding, washing and curing are minutes of skilled attention per part, and at batch scale they rival the print itself. Enter them at an honest labour value; entering zero is a decision that your time is worthless, which the totals will then faithfully reflect.
- Batch size is the setup lever. Setup divides across the batch, so per-part cost falls as quantity rises, until failure risk and machine occupancy argue back. Run 1, 10 and 100 parts here before quoting any of them; the three per-part figures tell you where your pricing tiers should sit.
How it is calculated
- Material (batch) = parts x grams per part x price per kilogram / 1,000. Machine (batch) = parts x hours per part x machine rate. Electricity (batch) = parts x hours per part x watts / 1,000 x price per kWh. Print cost = those three summed.
- Failure adjustment: print cost divided by (1 – failure rate). The failure allowance line is the increase. Post-processing = parts x per-part figure. Setup and other batch costs enter flat. Batch total = adjusted print cost + post-processing + setup + other. Cost per good part = batch total / parts. Every amount rounded to cents at its line.
Worked examples
Ten parts in PLA. Illustrative figures: 10 good parts at 42 grams each is 420 grams; at $24 a kilogram the material is $10.08. Print time 3.2 hours a part at a machine rate of $0.85 is $27.20 for the batch. Power at 120 watts across 32 batch hours is 3.84 kWh, at $0.16 costing $0.61. Print cost $37.89. At a 15% failure rate the cost divides by 0.85 to $44.58, a failure allowance of $6.69. Post-processing at $1.35 a part adds $13.50, setup $6.00, for a batch total of $64.08 and a cost per good part of $6.41.
What the naive figure would have said. Filament alone per part is $1.01, the number hobby arithmetic quotes. The true part costs $6.41, over six times more, and the gap is not padding: it is 32 hours of a machine’s life, the prints that failed at 15%, and thirteen dollars of human finishing time. Businesses that price from filament discover this gap across a quarter of orders; this page exists to discover it across one minute of arithmetic instead.
One part, same settings. A single good part carries the whole $6.00 setup and the full failure grossing-up on one print: its cost works out materially higher per part than the batch of ten (run it and see the setup’s weight), which is why one-off prints and batches are different products even off the same printer and file.
Reading your results
Read the failure allowance line as a process grade. At a few percent it is noise; at twenty it is the second largest cost on the page and an instruction to fix the process (adhesion, calibration, material dryness) before negotiating any price, because no pricing survives a process that throws away a fifth of its machine hours. Then read machine cost against material: on most desktop printing the machine hours quietly outweigh the plastic, which is why print speed and reliability, not filament shopping, are where the savings live. Finally, hold the per-good-part figure against the alternatives (buying the part, a printing service’s quote) knowing yours now contains everything theirs contains.
Limitations
- Slicer estimates are estimates. Real prints vary with firmware behaviour, material batch and environment; the grams and hours here are as good as the profile behind them. Costing a production part deserves one weighed, timed physical print before the rate is trusted at volume.
- Failure timing is simplified. The grossing-up assumes failed prints consume a full print’s cost, though many fail early and cheap while a few fail at 95% and ruin a day. It is the correct expected value over a batch and the wrong story for any single failure, which is the nature of averages honestly used.
- Resin processes carry extra real costs. Washing solvent, curing, gloves and ventilation, and the safe disposal of resin waste belong in the per-part finishing and other batch costs. The fields hold them; the discipline of entering them is yours.
- The machine rate excludes your rent and your profit. This page totals cost. Pricing for sale adds margin and overhead recovery on top of the figures here, and confusing the cost per part with a price per part is the final way the arithmetic gets misread.
Frequently asked questions
How do I work out my machine rate per hour?
Divide what the machine costs to own by the hours it will realistically print. Purchase price plus expected maintenance, nozzles, beds and belts across its life, divided by lifetime print hours, gives the rate: a $500 printer printing 2,000 lifetime hours with $100 of consumables in that span runs at $0.30 an hour before electricity, which this page adds separately from wattage. Commercial machines with service contracts simply divide the contract and capital by the same hours. The worked example’s $0.85 suits a mid-range machine worked moderately; your figure comes from your machine’s own arithmetic.
Why does a 15% failure rate raise costs by more than 15%?
Because failures consume attempts, and good parts must pay for the attempts that produced nothing. Producing 100 good parts at a 15% failure rate takes about 118 attempts, so the print cost per good part is the attempt cost divided by 0.85, a rise of about 17.6%, not 15. Adding 15% on top, the intuitive shortcut, underprices every batch, and the error grows with the rate: at 30% failures the true multiplier is 1.43 against the shortcut’s 1.30. The page uses the division because it is the arithmetic of the process, not an approximation of it.
Is electricity worth including at all?
Sixty-one cents on a $64.08 batch in the worked example says the honest answer is barely, and the page includes it anyway for two reasons: at industrial scale and long print times it stops being trivial (a 40 hour print at 300 watts is 12 kWh), and a costing discipline that includes the small real cost it can see is the same discipline that remembers the large ones. Excluding it deliberately, with its size known, is a decision; never having computed it is an oversight.
What is the difference between cost per part and cost per good part?
Everything this page adds beyond the slicer. Cost per part, naively, is one print’s filament, perhaps $1.01 on the example. Cost per good part is the batch’s full cost divided by the good parts it yields: $6.41, carrying machine life, power, the failed attempts at their true grossed-up weight, finishing and setup. Quotes, prices and make-or-buy decisions are only sound on the second figure, and the persistent gap between the two numbers is why printing businesses fail with full order books.
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Method: batch costing from slicer quantities at user-entered rates, failures grossed up by division by the success rate on print costs only, per-good-part figure from the full batch total, exactly as defined on this page. Last reviewed: 13 October 2026.