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

Multi-Colour Print Calculator

Calculate total filament including waste for multi-colour 3D prints with purge tower waste and cost comparison.

Filament Swap Calculator

Calculate purge waste and time for multi-colour filament changes mid-print.

Filament Length Calculator

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

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.

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Last updated: February 2026

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