The real cost of a 3D print

There are two numbers for a part: what it costs you, and what you invoice. The guide “How much should you charge” is about the second. This one is about the first — the cost price — because you cannot know whether you make money without knowing it, and almost nobody works it out.

Material: the one cost everyone counts

The spool price divided by a thousand, plus supports, purges and failures: €0.035/g for PLA, €0.04/g for PETG in practice, and resin per millilitre. It is detailed in the guide “Price per gram”. Let's keep in mind that on a 33 g PETG part, it is €1.34.

Electricity: small per part, not per year

An open FDM printer printing PLA draws 80 to 120 W on average, bed heating included; PETG or ABS in an enclosure, 150 to 250 W. A resin printer, 50 to 80 W, plus the wash and cure station. At your local rate (around €0.20 per kWh in France — check your bill, it moves), two hours of PETG printing cost 0.3 kWh, about 6 cents. Nothing per part. But a machine running 2,000 hours a year is €60 to €100 of electricity — out of your pocket if you count it nowhere.

Wear: what the machine loses every hour

Two things wear out: the machine itself, and its consumable parts.

Depreciation. A €600 printer that will do 4,000 hours in its life loses €0.15 per printing hour. A machine costing 1,200 euros and doing 6,000 hours, €0.20. It is not an expense you see go by; it is the next machine you will have to buy.

Consumables. Nozzles (€5 to €20 each, several a year with abrasive materials), PEI sheet (€20 to €40, one a year), belts, fans, PTFE tube, a full hotend: count €50 to €100 a year for a working machine, or €0.03 to €0.10 per hour. For resin it is worse and nobody says so: the FEP film (€5 to €10, every 20 to 30 vats), and above all the LCD screen, which is a consumable — 1,000 to 2,000 hours of life, €50 to €150 to replace, or €0.05 to €0.10 per hour of exposure.

All in, the real wear of an ordinary FDM machine is around €0.20 to €0.25 per hour. That is what I ended up putting in my rates (€0.15 of wear, the rest included in the machine hour), after charging €0.50 for a long time — too much, and I couldn't justify it.

Failures: a percentage on everything else

A failure costs its material, its electricity, its wear, and your time to notice it, clean up and restart. With a well-tuned machine and known parts, 5% of prints go in the bin; with new parts or difficult materials, 10% and more. The right reflex is not to guess that rate: it is to measure it on your real history — prints launched, parts delivered — and apply it to every quote. A measured rate of 7% adds 7% to every item above.

Your time: the cost nobody counts

Starting the print, checking the first layer, coming back to remove the part, cleaning the plate, tidying up: 5 to 10 minutes per print, whatever its size. At €18 an hour — the minimum for a craftsman — that is €1.50 to €3 per print. That is why a small 3 g part cannot be sold for €2: the material is worth 10 cents, but your ten minutes are worth €3. And that time includes neither post-processing, nor design, nor the quote itself.

The full example, on a real part

My awning part: 2.12 h of printing, 33.53 g of PETG, a €600 machine.

Four euros thirty-one, with no margin, no modelling, no file analysis, no post-processing: that is the floor. Below it, every part sold loses you money. The price itself is built in the guide “How much should you charge for a 3D print?”.

What to do with it

This calculation has to be done once, seriously, machine by machine, then left to run. ForgeCalc keeps it up to date in the cost sheet of every quote — material, energy, depreciation, machine occupation, failure rate measured on your history — and that sheet stays with you: it never appears on a document sent to the customer.