3D Print Filament Calculator — Estimate Filament Usage

Estimating 3D Print Filament Usage

Knowing how much filament a 3D print will consume before you start is essential for avoiding mid-print runouts and managing material costs. This calculator estimates filament weight, length, and cost based on the print volume, infill percentage, wall thickness, and the density of your chosen filament material. It accounts for both the solid outer shell and the partially filled interior.

The calculation works by combining wall volume with infill volume. The outer walls of a print are solid, while the interior is filled at whatever infill percentage you select. A 20% infill means only 20% of the interior volume is filled with plastic, dramatically reducing material use compared to a solid print. The total material volume is then multiplied by the filament density (PLA is 1.24 g/cm3, ABS is 1.04 g/cm3, PETG is 1.27 g/cm3) to get the weight in grams, which is converted to filament length using the cross-sectional area of the filament diameter.

This tool is particularly useful for budgeting multi-part projects and deciding whether you have enough filament left on a spool for your next print. Keep in mind that slicer estimates may differ slightly because they account for support structures, brims, and skirts. For the most accurate pre-print estimate, check your slicer output, but this calculator gives you a reliable ballpark figure for planning material purchases and comparing costs across different filament types.