¿Cuánto cuesta la hora de impresión 3D?
La hora de una impresora FDM cuesta R$ 0,63: depreciación, energía y reserva por fallos. El cálculo completo, y por qué cobrar por hora suele ser un error.
Short answer: a 1 kg spool of PLA in 1.75 mm holds about 335 metres (1,100 ft). PETG gives ~327 m, ABS ~400 m, TPU ~344 m. The difference isn't the brand — it's the density of the plastic. Below is the table for every material, how many parts a spool actually makes, and the formula to work it out for your own roll.
How many metres are in 1 kg of filament
Filament is a long cylinder. Each metre weighs the density of the plastic times the cross-sectional area. Since density changes from material to material, the same kilo gives very different lengths.
| Material | Density | Grams per metre | Metres per kg |
|---|---|---|---|
| ABS | 1.04 g/cm³ | 2.50 g | ~400 m |
| ASA | 1.07 g/cm³ | 2.57 g | ~389 m |
| Nylon (PA6) | 1.14 g/cm³ | 2.74 g | ~365 m |
| TPU (95A) | 1.21 g/cm³ | 2.91 g | ~344 m |
| PLA | 1.24 g/cm³ | 2.98 g | ~335 m |
| PETG | 1.27 g/cm³ | 3.05 g | ~327 m |
Note what that contradicts: ABS gives MORE metres per kilo than PLA, not fewer. It's the least dense material on the list, so the same weight yields about 65 metres more. That's the opposite of what most people assume — and of what a lot of articles repeat.
The formula, for your own spool
If your filament is a specialty blend — PLA+, silk, matte, carbon-fibre or wood-filled — the density shifts and the table above becomes an approximation. The formula is simple:
metres per kg = 1000 ÷ (density × 2.405)
The 2.405 is the cross-sectional area of 1.75 mm filament, in cm². Density is usually on the manufacturer's data sheet. If it isn't, measure it: weigh exactly one metre on a precision scale and divide by 0.02405 — that gives density in g/cm³.
What about 2.85 mm filament
2.85 mm filament (still used on Ultimaker and some older machines) has a cross-section 2.65 times larger. The same kilo gives 2.65 times fewer metres: 1 kg of PLA in 2.85 mm is about 126 metres, not 335. Same weight, much shorter roll — but the volume of plastic is identical, so the number of parts doesn't change.
How many parts come out of 1 kg
Metres aren't the useful unit when you're quoting a job. Parts are. These figures assume 15% infill and 2 perimeters, the default most slicers use for decorative pieces:
| Part | Typical weight | Per kg |
|---|---|---|
| Keychain / small figurine (~5 cm) | 8–15 g | 65 to 125 |
| Desk figurine (~6 cm) | 15–30 g | 33 to 65 |
| Phone stand | 40–80 g | 12 to 25 |
| Medium decorative vase (15 cm) | 80–150 g | 6 to 12 |
| Drawer organiser | 120–200 g | 5 to 8 |
| Large functional part (case, cabinet) | 150–300 g | 3 to 6 |
| Cosplay helmet (printed in sections) | 600–900 g | 1, with little left over |
What makes a spool run out faster
- Infill. This is the big one. Going from 15% to 50% nearly doubles the material in the same part. For decorative work 15% is plenty; above 30% only makes sense on parts that take load.
- Supports. Heavy overhangs burn filament that goes straight in the bin — on a complex model, supports reach 30% of what you spent. Rotating the part in the slicer often removes almost all of it.
- Perimeters. Every extra wall adds grams across the whole surface. Three walls at 15% infill usually makes a stronger — and lighter — part than two walls at 40%.
- Colour-change purge. On multi-colour printing with an AMS, every swap flushes filament to clean the nozzle. On a part with many changes, waste passes 30% of the spool.
- Failed prints. The part that peels off at layer 200 took the material with it. That's why any serious cost estimate keeps a margin for failure.
What each part actually costs
At $15 to $20 per kilo, each gram costs about 1.5 to 2 cents in material. So that 20 g figurine is well under a dollar in plastic.
But material isn't cost. Adding power, nozzle and build-plate wear, and a reserve for failed prints, real production cost lands between 3 and 5 cents per gram — roughly double the filament alone. Anyone quoting on plastic only is working for free.
Instead of using these averages, run your own numbers: the FDM cost calculator takes your filament price, your electricity rate and your machine's depreciation — and exports a PDF quote for the client.
How much is left on a half-used spool
A question that comes up every week, and the answer is a kitchen scale. Weigh the whole spool and subtract the empty spool weight — usually printed on the label, and typically 180 to 250 g for a plastic core. What's left is filament.
With the grams in hand, the table above already tells you how many parts remain. For metres, multiply grams by the factor from the first table: 335 ÷ 1000 for PLA, so 400 g of PLA ≈ 134 metres.
Which filament to buy
For beginners and for ninety per cent of parts, PLA: easy to print, doesn't warp, needs no enclosure, and it's the cheapest. PETG when the part will see sun or heat. ABS and ASA only with an enclosed machine.
- ELEGOO PLA+ Filament 1.75 mm (1 kg) — PLA+ takes impact better than plain PLA at the same price. It's the one our readers buy most.
- ELEGOO PETG Filament, black, 1.75 mm (1 kg) — for parts that live in a car, a window or outdoors.
One warning that saves spools: PLA and PETG absorb moisture. Filament left open for weeks pops at the nozzle, prints dull and brittle, and the owner blames the printer. A sealed bag with desiccant prevents it; an already-wet spool needs drying.
Want the full cost per part, not just filament? See How Much Does 3D Printing Cost. Still choosing a machine? The 10 best 3D printers of 2026 or the printer database.
Densities checked against manufacturer data sheets; specialty spools (silk, matte, fibre- or wood-filled) vary by a few per cent. We participate in the Amazon and AliExpress affiliate programmes and earn from qualifying purchases made through the links above.
