Filament Calculator
Use this free filament calculator to check your spool, convert grams to meters, and estimate material cost for your next 3D print.
Check your spool
Start with the example, then enter your measurements. Results update as you type.
Know your spool.
Skip the guesswork.
A scale, your empty spool weight, and your slicer’s estimate are all you need.
Weigh the whole spool
Put the spool and remaining filament on a scale. Enter the total in grams, then subtract the empty spool weight. Spools vary, so don’t use a universal tare.
Bring your slicer estimate
Enter the filament needed for the complete job, including supports, brim and purge. Add a safety allowance for a little breathing room.
Compare before committing
See whether the spool covers your print and allowance. Use the other tabs to convert length or calculate material cost.
How the filament calculator works
Remaining material is a direct weight calculation. Converting between weight and length also uses the filament’s diameter and density.
For length in meters, weight in grams, diameter in millimeters, and density in g/cm³:
Example: 1,000 g of 1.75 mm PLA at 1.24 g/cm³ is approximately 335 m. These are estimates; use measured diameter and manufacturer density when available.
What will your next print cost?
Use the filament cost calculator to assign part of a spool’s price to a print. Enter the net filament weight on the spool, its price, and the print’s consumption.
A 180 g print from a 1,000 g spool costing $24.99 uses about $4.50 of filament. Select USD or CAD to display your local currency; the tool does not convert exchange rates.
Keep estimates realistic
Specialty blends can have different densities. Supports and multicolor purge add material. The cost result excludes electricity, labor and printer wear.
Remaining filament calculator
Use this free online 3D printer filament calculator before starting a job on a partly used spool. It compares the material left with your print requirement plus a safety allowance. For multiple parts, enter the combined filament usage from your slicer.
PLA filament calculator
Choose PLA as a starting point for standard PLA filament, then check the density against your manufacturer’s specifications. Silk, foaming, wood-filled and other modified filaments may need a different value. The same process works for PETG, ABS and custom materials.
Filament weight and length calculator
The weight-to-length option converts grams of filament to meters. The filament length to weight calculator reverses that calculation. Both depend on diameter and density; the plastic spool’s weight must be excluded.
Filament cost and price
The free 3D print cost calculator estimates the filament portion of your project’s cost. Use the price you actually paid and the spool’s net filament weight. It helps compare material expenses, but it does not set a selling price for your finished print.
How many meters of filament are in 1 kg?
A kilogram measures weight, so its length depends on the filament’s thickness and density. These estimates use the same approximate density presets and formula as the calculator.
| Material | Density (g/cm³) | 1.75 mm diameter | 2.85 mm diameter |
|---|---|---|---|
| PLA | 1.24 | 335 m | 126 m |
| PETG | 1.27 | 327 m | 123 m |
| ABS | 1.04 | 400 m | 151 m |
Rounded to the nearest meter. These are examples, not manufacturer specifications. For filled or specialty blends, enter the density from your filament’s data sheet.
How much filament does a 3D printer use?
The print settings and model determine consumption. Size, wall thickness, infill, supports, brim and purge all contribute. Slice the complete job first, then use the reported grams in the remaining filament or material cost calculator.
How long will a 1 kg spool last?
Divide the net filament available by the total material used per job. If a complete job uses 50 g, a full 1,000 g spool theoretically covers 20 jobs before allowing for additional waste or failed prints. A spool does not have a fixed number of printing hours.
Filament calculator FAQs
How do I calculate how much filament is left on a spool?
Weigh the spool with its remaining filament, then subtract the weight of the empty spool. For example, 480 g total minus a 200 g empty spool leaves 280 g of filament. Use the tare weight for the exact spool you have.
How many meters are in 1 kg of PLA filament?
At 1.75 mm diameter and a density of 1.24 g/cm³, 1 kg is approximately 335 meters. At 2.85 mm diameter it is approximately 126 meters. Different materials and actual diameters change the result.
Does this filament calculator work with PETG and ABS?
Yes. Choose a material preset or enter a custom density. The starting values are approximate: PLA 1.24, PETG 1.27 and ABS 1.04 g/cm³. Blends, fillers and manufacturer formulations can differ, so check your filament’s data sheet.
Can I calculate filament usage from an STL file?
An STL describes geometry, not the complete print instructions. Infill, walls, layer height, supports and purge settings affect consumption. Slice your model first, then enter the slicer’s estimated filament weight here.
What does the safety allowance do?
It adds a percentage to the slicer’s print requirement when checking your remaining spool. A 180 g print with a 10% allowance needs 198 g. This is a planning buffer, not a guarantee that a print will finish.
Does material cost include electricity or printer wear?
No. This calculator estimates filament cost only. A full print price may also include electricity, machine time, labor, failed prints, packaging and profit.
Is the calculator free, and are my measurements uploaded?
The calculator is free to use. Calculations run in your browser, and this site’s calculator does not upload your input values. Your light or dark theme choice is stored on your device.
Can I use this with a Prusa or Bambu Lab printer?
Yes. Enter your filament diameter and density, the actual empty spool weight, and your slicer’s estimated print consumption in grams. The calculations do not depend on the printer brand. This independent calculator is not affiliated with Prusa or Bambu Lab and does not connect to your printer.
Is this a G-code or STL filament calculator?
This tool does not read STL or G-code files. Use your slicer to estimate the material required for the job, then enter that weight to check your spool or calculate material cost. It also works for projects such as Multiboard when you enter the total requirement for all the pieces you plan to print.
How do I use the filament length to weight calculator?
Open Weight ↔ length and choose Length → weight. Enter the length in meters, filament diameter in millimeters, and density in g/cm³. The result is the estimated filament weight in grams, excluding the spool. Choose Weight → length to convert in the other direction.
Does this calculate filament shrinkage or volumetric speed?
No. These calculators cover remaining filament, weight and length conversion, and filament cost. They do not calculate shrinkage compensation, flow limits or print speed.