About this tool
Slicers report filament use sometimes in grams and sometimes in metres, and spools are sold by weight. The Filament Calculator converts between weight, length, volume and cost. It uses the cross-section of the filament (the circle area from the diameter) times the density of the material: 1 m of 1.75 mm PLA weighs about 2.98 g, and a 1 kg spool holds around 335 m.
In “Left on spool” mode you weigh the partly used spool and subtract the weight of the empty spool. That tells you whether the length is enough for the next print. Everything is calculated right in your browser.
How it works
- Choose whether to convert from weight or length, or to find out what is left on a spool.
- Enter the amount, or for the remaining filament the weight of the spool and of an empty spool.
- Pick the material and diameter; for the cost, enter the spool price and the amount of filament per spool.
- Read the length, weight, volume and cost.
Frequently asked questions
How many metres are on a 1 kg spool?
With 1.75 mm about 335 m of PLA, 327 m of PETG and around 400 m of ABS, because ABS is lighter. With 2.85 mm it is only about 126 m of PLA, as the cross-section is almost three times larger.
Which densities does the calculator use?
Typical values in g/cm³: PLA 1.24, PETG 1.27, ABS 1.04, ASA 1.07, TPU 1.21, PA (nylon) 1.14, PC 1.20 and PVA 1.23. For other materials or blends choose “Custom density” and enter the value from the data sheet.
How heavy is an empty spool?
Depending on brand and material usually between 150 and 250 g; cardboard spools are lighter. Best weigh an empty spool of the same brand and note the value.
How do I calculate the total cost of a print?
The Filament Calculator only gives the material cost. The 3D Print Cost Calculator adds electricity, printer wear, failed prints and a markup.