3D Print Nozzle Flow Calculator

About this calculator

A 3D printer's volumetric flow rate is how fast molten filament passes through the nozzle, calculated as layer height × line width × print speed. Every hotend has a maximum melt flow rate — how fast it can actually heat and push plastic — typically 10-15 mm³/s for a stock brass nozzle on filaments like PLA, and lower for harder materials like PETG or ABS.

This calculator computes your print's required flow rate from your slicer settings and compares it against your hotend's rated max melt flow, warning you if you're asking for more plastic than the hotend can melt in time — a common cause of under-extrusion and skipped layers. 3D printing hobbyists tuning print speeds use it to push speed as high as possible without exceeding what the hardware can actually deliver.