About this tool
3D Printer Filament Calculator is a free, in-browser tool that converts filament between length, weight, volume and cost. Pick your material and filament diameter, then enter a weight to get the length (and cost), or switch modes and enter a length to get the weight — everything is computed locally as you type, with nothing uploaded.
Filament is a solid cylinder, so its cross-section area is A = π·(d/2)², where d is the filament diameter (1.75 or 2.85 mm). The mass per millimetre of filament is density · A ÷ 1000, using each material's density in g/cm³ (PLA 1.24, ABS 1.04, PETG 1.27, TPU 1.21, Nylon 1.14, ASA 1.07). Length then follows as weight ÷ mass-per-mm, and weight as mass-per-mm × length; the cost tile is weight ÷ 1000 × your price per kg.
Use it to check how much of a spool a model needs, to convert a slicer's gram estimate into metres of filament, or to price a print. Because 1 kg of 1.75 mm PLA is roughly 335 m, a 100 g part comes out near 33.5 m — the tool shows the exact figure for your chosen material and diameter.