What this calculator does
Every 3D print consumes a predictable amount of filament: the model volume the slicer reports, multiplied by the density of whichever material is loaded. Filament is sold by weight, so knowing the expected weight before a print starts is what turns a spool price into an actual cost per job.
The catch is that "model volume" in a slicer already accounts for infill, walls and top/bottom layers, it is not the solid volume of the shape you designed. This calculator treats the volume you enter as the print volume, and includes an adjustment factor for the rare case where you are instead working from a solid CAD volume and need to scale it down yourself.
The formula
Multiply the model volume by the density of the chosen filament material, then by the adjustment factor, to get weight in grams. Divide that weight by 1,000 and multiply by the price per kilogram to get the cost.
| Term | Meaning |
|---|---|
| Model volume | The volume of plastic the print will actually use, as reported by the slicer for the current infill and wall settings. |
| Density | Grams per cubic centimetre for the chosen filament type: a fixed material property, not something that varies by brand or colour. |
| Adjustment factor | A multiplier left at 1 when the entered volume already reflects the real infill; used only if entering a solid model volume instead. |
The inputs explained
| Field | What to enter |
|---|---|
| Model volume (from slicer) (cm³) | The print volume as shown by your slicer, in cubic centimetres, for the current infill and wall settings. |
| Filament type | The loaded filament material. Densities are standard published values for each material. |
| Infill adjustment factor (1 = slicer volume already reflects infill) | Leave at 1 if the volume entered already reflects the slicer’s infill calculation. |
| Filament price ($/kg) | The price you pay per kilogram of that filament, including any shipping if you buy that way. |
When to use it
Quoting a print job
Before starting a print for someone else, converting the slicer’s volume estimate into a dollar figure gives a defensible number to quote, rather than guessing at a spool fraction.
Comparing materials for the same model
Because PLA, PETG, ABS and TPU all have different densities, the same model volume comes out at a different weight and cost depending on which material is loaded.
Budgeting for a batch of prints
Multiplying the per-print weight by the number of copies needed shows how much of a spool, or how many spools, a production run will use.
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How filament weight and cost change with model volume, by material
A fixed filament price, across a range of model volumes, for PLA.
| Model volume | Filament weight | Estimated cost |
|---|---|---|
| 10 cm³ | 12.4 g | $0.31 |
| 20 cm³ | 24.8 g | $0.62 |
| 40 cm³ | 49.6 g | $1.24 |
| 60 cm³ | 74.4 g | $1.86 |
| 100 cm³ | 124.0 g | $3.10 |
| 150 cm³ | 186.0 g | $4.65 |
How weight changes with filament material at a fixed model volume
The same 40 cm³ print volume, switching between the four listed materials.
Questions
Why does the calculator not just multiply weight by cost per kilogram directly?
It does, once weight is known: cost is weight in kilograms multiplied by the price per kilogram. The extra step is only in getting from volume to weight in the first place, which needs the material density.
Should I use the slicer’s time estimate or its volume/weight estimate for costing?
The volume or weight figure is the more reliable one for material cost, since it is a direct geometric calculation. Time estimates are more sensitive to travel moves and print settings and are better suited to the print time calculator.
Do filament densities vary much between brands?
Only slightly. The published values used here (PLA 1.24, ABS 1.04, PETG 1.27, TPU 1.21 g/cm³) are standard figures for each polymer and are close enough for costing purposes across brands.
What if my slicer only reports weight, not volume?
Enter the weight directly here is not supported since this calculator starts from volume, but you can back-calculate: divide the slicer’s reported weight by density to get an equivalent volume, or simply multiply the reported weight by price per gram yourself.
For how long that same print will take on your printer, see the print time estimate calculator. To work out the infill share of the volume itself, see the infill volume calculator.