Print Volumetric Flow Rate Calculator

The setting that actually limits print speed

Print speed alone does not determine whether a hot end can keep up - what matters is volumetric flow rate, the actual amount of molten plastic being pushed out per second, which depends on layer height, line width, and speed together.

Typical hot end flow limits

Hot End Type	Approximate Max Flow
Stock brass nozzle (0.4mm)	8 - 12 mm³/s
Volcano-style long melt zone	15 - 24 mm³/s
Hardened steel, high-flow (e.g. CHT)	20 - 32 mm³/s
Dedicated high-speed hotends	30+ mm³/s

Worked example

At 0.2mm layer height, 0.4mm line width, and 60mm/s print speed:

Flow = 0.2 x 0.4 x 60 = 4.8 mm³/s

This is comfortably within range for nearly any stock hot end. Pushing print speed up to 150mm/s at the same layer height and line width would require 12 mm³/s, right at the edge of what a stock brass nozzle can reliably melt.