Density and price of 3D printing filaments
The density of each material, what a kilo costs and how many metres it gives. The three numbers that move the cost of your parts.
Density decides how many metres a kilo holds, and price per kilo decides what each gram costs you. With those two numbers and the weight of your part you already have the material cost; the rest — power, machine, failures — is what the 3D printing cost calculator adds.
| Material | Density (g/cm³) | Price per kg | Metres per kg (1.75 mm) | Good for |
|---|---|---|---|---|
| PLA | 1.24 | $15 – $25 | 335 m | Decorative parts, prototypes, anything that won't get hot. |
| PLA+ | 1.24 | $18 – $28 | 335 m | Same as PLA but it takes a knock far better. |
| PETG | 1.27 | $18 – $28 | 327 m | Functional parts, outdoors, contact with water. |
| ABS | 1.04 | $18 – $30 | 400 m | Parts that take heat. Needs an enclosure. |
| ASA | 1.07 | $22 – $38 | 389 m | Proper outdoor use: it doesn't yellow in the sun. |
| TPU (flexible) | 1.21 | $25 – $45 | 344 m | Cases, wheels, gaskets, anything that bends. |
| Nylon (PA) | 1.14 | $30 – $60 | 365 m | Gears and rubbing parts. Soaks up moisture. |
| PC (polycarbonate) | 1.20 | $35 – $65 | 346 m | Hard, clear parts that take a beating. |
| Wood / PLA | 1.15 | $25 – $40 | 362 m | Wood-like finish. Wears the nozzle down. |
| Carbon fibre / PETG | 1.30 | $35 – $60 | 320 m | High stiffness. Needs a hardened steel nozzle. |
The prices are brackets, not a price list
Filament prices move a lot: between brands, between colours from the same maker, between a Black Friday deal and a one-off purchase. The ranges in the table are ballpark figures for a normal purchase. A supermarket-brand PLA on offer can drop below $15/kg and a premium PLA with a special finish passes $30/kg without blinking. Use the bracket to get your bearings and always type what your spool actually cost you into the calculator.
Why density matters more than it looks
Picture the same part printed in ABS (1.04 g/cm³) and in PETG (1.27 g/cm³). The same volume of plastic weighs 22% more in PETG, so you spend 22% more grams and the material costs you 22% more, even if both kilos cost the same. The other way round: a kilo of ABS gives you about 400 metres and a kilo of PETG about 327. If you buy by the kilo and plan by the metre — or the other way round — that gap lands straight in your price.
Which one to pick, in one line each
- PLA: easy, cheap and enough for nearly anything decorative. Warps in a car in the sun.
- PLA+: same cost to print with far less brittleness.
- PETG: the natural step up for functional parts, outdoors and water contact.
- ABS and ASA: heat and sun resistant, but they want an enclosure and ventilation.
- TPU: flexible; prints slowly and not every machine feeds it well.
- Nylon and PC: serious mechanics, high temperatures and compulsory drying.
- Filled ones (wood, carbon fibre): finish or stiffness in exchange for nozzle wear; with carbon fibre, a hardened steel nozzle is not optional.
Careful with the density of filled filaments
A «wood PLA» isn't PLA: it carries fibre particles that change its density, and the same goes for carbon-filled, metal-filled or foaming filaments (LW-PLA), whose effective density drops enormously when printed because the material expands. In those cases the number in the table is an approximation: check what the manufacturer says and type it into the density field by hand.
How much the final cost changes by material
Less than people fear. On a 60 gram part that takes five hours, moving from PLA at $20/kg to PETG at $24/kg puts the total cost up about 25 cents, because material is only part of the total. Moving to nylon at $45/kg puts it up around $1.65. Check it with your own numbers in the calculator, which has a button to compare two materials side by side, or look at the costs of 20 typical parts.
Want the exact number for your own case? 3D printing cost calculator does the full sum with your filament, your electricity tariff and your printer, and leaves the quote ready to copy.
Frequently asked questions
What is the density of PLA?
1.24 g/cm³ for standard PLA, and the same value for PLA+.
At that density, a kilo of 1.75 mm PLA gives about 335 metres of filament.
How much does a kilo of filament cost?
A normal-grade PLA runs between $15 and $25 a kilo, and PETG between $18 and $28.
Technical materials climb steeply: nylon runs $30 to $60 and polycarbonate can pass $65.
Which is stronger, PLA or PETG?
PETG takes impacts, heat and humidity far better; PLA is stiffer but more brittle and softens from about 55-60 °C.
For functional or outdoor parts, PETG; for figures and decoration, PLA.
Why does ABS give more metres per kilo?
Because it is less dense: 1.04 g/cm³ against PLA's 1.24.
The same kilo takes up more volume and therefore more length of strand: about 400 metres against 335.
Does density affect the weight of the printed part?
Yes, directly. The same part at the same infill weighs more in PETG than in ABS.
Since filament is sold by weight, that changes the material cost even if the price per kilo is identical.
What density do I use if my filament isn't listed?
Check the manufacturer's data sheet: density is usually quoted in g/cm³.
The density field in the tools is editable for exactly that reason; if you can't find the figure, 1.24 is a reasonable approximation for any PLA variant.
More tools and guides
- 3D printing cost calculatorWork out the real cost and selling price of a 3D printed part: material, power, machine and markup. Free, no sign-up.
- How much electricity does a 3D printer useWork out your 3D printer's electricity use and what it costs per month on your own tariff. Free and instant.
- Filament grams to metres converterConvert grams of filament to metres by material and diameter (1.75 / 2.85 mm). Instant calculation, no sign-up.
- How much to charge for a 3D printed partPrice your 3D printed parts properly: real cost + labour + markup. Free, no sign-up, with a quote ready to send.
- How much does 3D printing cost: 20 parts with real numbersThe real cost of 20 typical 3D printed parts: keyring, planter, phone stand, gear and more.
- How long does a 1 kg filament spool lastHow many metres and how many parts you get from a 1 kg spool, by material and diameter.