Price per gram of PLA, PETG and resin in 2026

Everyone looks for this number, and everyone gets it wrong the same way: by dividing the spool price by a thousand. Here is the raw price, then the real price once supports, purges and failures are counted — and why, even when right, this number is not the price of a part.

The raw price: the spool divided by 1,000

The ranges below are what I see at French retailers for a 1 kg spool, promotions excluded. They move by a few euros with colour and timing; the order of magnitude doesn't.

Resin is counted per millilitre, never per gram: the slicer reports millilitres, and a one-kilo bottle holds only about 900 ml (density around 1.1).

Why raw is not real

A gram bought is not a gram sold. Between the spool and the delivered part there are:

Supports. 5 to 20% of the part's weight depending on its geometry, straight into the bin. On a part that needs them, it is the first source of loss.

Purges, skirts and brims. A purge line, a few loops of skirt, a brim for adhesion: 1 to 3 g per print. On a 10 g part, that is 20%.

Failures. Even with a well-tuned machine, one print in fifteen or twenty goes in the bin: lifting, clog, power cut. For a new part, more. A professional counts 5 to 10%.

Spool ends. The last 20 to 50 grams, too short for a part, end up in calibrations or scrap. On a kilo, that is 2 to 5%.

Moisture. PETG or nylon that has taken on moisture strings, bubbles, and gets thrown out. Spools you dry cost power; spools you don't dry cost parts.

For resin, add the isopropyl alcohol for washing (counted per millilitre too), the resin left in the vat and filtered, the resin that leaves with supports and failed prints stuck to the film, and the gloves.

Added up, these losses are 30 to 50% on top of the raw price. That is why ForgeCalc's default material rate is €0.035/g for PLA, €0.04/g for PETG, and €0.04 to €0.085/ml for resin depending on the type: the raw price of a common spool, plus what it really costs to turn into parts. These are my figures; everyone sets their own.

What it comes to on a real part

My awning part weighs 33.53 g in PETG. Raw, at €0.025/g: €0.84. Real, at €0.04/g: €1.34. And its selling price, all in, is €9.27 — material is 14% of it. The rest is machine, wear, time, design: the breakdown is in the guide “How much should you charge for a 3D print?”.

Should you buy the cheapest filament?

Between a €16 spool and a €24 spool, the gap is €0.008/g, or €0.27 on this part. A nozzle clogged by filament of uneven quality is an hour of work lost, and sometimes a failed part after ten hours of printing. Cheap filament pays off on short parts and prototypes; on a twelve-hour part for a customer, it no longer does. It is a choice per part, not a matter of principle.

For resin: per millilitre, and not only the resin

A standard resin at €25 per kilo comes to €0.028/ml raw. Real, with washing, supports and failures: €0.04/ml. And post-processing a resin part — washing, drying, UV curing, sanding the support marks — is time billed separately, as with filament, but rarely under a quarter of an hour per batch.