How do multi-colour prints work?

Multi-colour prints can be achieved through filament swaps at layer changes, using a multi-material system (like the Bambu AMS), or with a mixing hot end that blends colours in real time.

Can I blend filament colours in a single nozzle?

Only with a mixing hot end (like the Diamond or Prometheus). Standard single-nozzle printers do colour changes by pausing and swapping filament. Multi-material systems use separate nozzles or a Y-splitter.

How much purge waste does colour changing create?

Each colour change typically wastes 2-8cm of filament in purge. With many changes this adds up significantly. A 100-change print could waste 200-800cm of filament.

3DPrintCalcs

Colour Mixing Calculator — Multi-Colour Ratios

Calculate filament ratios by weight and length for multi-colour or gradient prints.

Total Filament Needed

Total filament mass for the whole print (take this from your slicer's estimate), in grams.

Colour 1 Ratio

Share of this colour in the print. The two ratios are normalised to 100% automatically, so 70/30 and 7/3 give the same split.

Colour 2 Ratio

Share of this colour in the print. The two ratios are normalised to 100% automatically, so 70/30 and 7/3 give the same split.

How We Calculate This

Calculation

The calculator normalises the colour percentages to ensure they sum to 100%, then splits the total filament weight proportionally:

Colour weight = Total weight x (Colour % / Sum of all %)
Colour length = (Weight / Density) / Cross-section area

Length estimates use the entered filament density (default 1.24 g/cm3 = PLA) and diameter (default 1.75mm). Change these in Advanced Options for PETG (1.27), ABS (1.04) or other materials.

Frequently Asked Questions

Related Calculators

Filament Length Calculator

Calculate the total length of filament on a spool from its weight and diameter.

Filament Weight Calculator

Estimate how much filament a print will use by weight from model volume.

Filament Cost Calculator

Work out the material cost of a print based on filament weight and spool price.

Spool Life Calculator

Estimate how many prints you can get from one spool of filament.

Filament Diameter Calculator

Calculate cross-sectional area and volume per metre for any filament diameter.

Last updated: February 2026

All calculations are estimates. Always verify settings with test prints before committing to final prints.