Nozzle Flow Rate Calculator

Calculate the maximum volumetric flow rate based on nozzle diameter, layer height, print speed, and line width.

How It Works

The volumetric flow rate is the volume of filament your hotend must melt and push through the nozzle per second. It determines whether your hotend can keep up with the requested print speed.

Formula

The required volumetric flow rate is calculated from the cross-section of the extruded line and the speed at which the nozzle travels:

• Volumetric Flow Rate = Layer Height × Line Width × Print Speed
• Result is in mm³/s (cubic millimeters per second)

For example, with a 0.2 mm layer height, 0.4 mm line width, and 60 mm/s print speed: 0.2 × 0.4 × 60 = 4.8 mm³/s.

Why It Matters

Every hotend has a maximum volumetric flow rate it can sustain. Exceeding this limit causes under-extrusion, grinding, and poor print quality. Knowing your required flow rate helps you:

• Choose appropriate print speeds for a given layer height and line width
• Determine the maximum speed before your hotend becomes the bottleneck
• Compare nozzle/hotend combinations for high-speed printing

Typical Hotend Flow Limits

• Standard V6-style hotend: ~11–15 mm³/s
• Volcano / high-flow hotend: ~20–30 mm³/s
• Bambu Lab / Revo high-flow: ~24–32 mm³/s
• SuperVolcano / CHT nozzle: ~35–50+ mm³/s

Layer Height Guidelines

Layer height should generally not exceed 75–80% of the nozzle diameter for good layer adhesion. Common pairings:

• 0.4 mm nozzle: 0.08–0.32 mm layer height
• 0.6 mm nozzle: 0.12–0.48 mm layer height
• 0.8 mm nozzle: 0.16–0.64 mm layer height