AMS Purge Waste Calculator

Calculate how much filament your Bambu Lab AMS wastes on colour transitions — in grams, cost, and as a percentage of your print weight. The hidden cost most multi-colour prints ignore.

Quick presets:

Print settings

Number of colour changes

Visible in Bambu Studio after slicing — check the layer preview timeline

Model print weight (g) — optional

From slicer — used to show waste as % of total print weight

Colour transition type

AMS model

Flush volume per change (mm³)

Bambu Studio default: 150mm³. Found under Filament → Flush volume.

Material

Price per gram (£)

Currency

Purge waste estimate

Enter the number of colour changes above to see purge waste.

How to reduce AMS purge waste

Order colours dark → light

Black before white needs far less purge than white before black. Plan your colour sequence before painting in Bambu Studio.

Lower flush multiplier for similar tones

Open the flush volume matrix in Bambu Studio and reduce the multiplier for pairs with similar brightness. Safe to drop to 0.5–0.7× for pastels.

Flush into infill

Enable "Flush into infill" to hide purge inside the model instead of building a wipe tower. Reduces visible waste but slightly affects internal structure.

Reduce total colour change count

If a layer alternates two colours repeatedly, rearrange geometry or use fewer colour regions. Each extra change multiplies your purge cost.

Calibrate flush with OrcaSlicer

OrcaSlicer has a dedicated flush calibration print. Run it per colour pair to find the true minimum flush volume before colour bleed appears.

Add purge to your selling price

For Etsy or print-service pricing, always add purge waste to material cost. On 35+ change prints it routinely adds 20–60% to filament spend.

FAQ

What is AMS purge waste and why does it matter?

Every time your Bambu Lab AMS switches filament colour, it must flush residual colour from the hotend to avoid contamination. This purged filament deposits into a wipe tower or into infill — and on detailed multi-colour prints the total waste can equal or exceed the weight of the model itself. Ignoring it leads to underpriced prints.

Why do dark-to-light transitions waste more filament?

Dark pigments (especially carbon-black-based colours like black and dark grey) contaminate the next colour strongly. Flushing black before white requires extruding a large volume of material before the residue clears. Light-to-dark is far more forgiving — dark colour masks any light residue instantly.

Where do I find the colour change count in Bambu Studio?

After slicing, look at the layer preview timeline at the bottom — each filament change icon represents one colour change. The total count also appears in the print statistics panel on the right side.

What flush volume should I use?

Bambu Studio defaults to around 150mm³ per slot-to-slot transition. You can tune this per colour pair in the flush volume matrix (Filament → Flush volume). For similar-coloured filaments you can safely drop to 80–100mm³; for black-to-white transitions 300–400mm³ is often needed for a clean result.

Does AMS Lite waste less than the standard AMS?

AMS Lite (A1 / A1 Mini) uses a filament cutter that reduces contamination slightly, allowing modestly lower flush volumes. In practice the colour-pair direction has a far larger effect than the AMS model — a bad dark-to-light transition will waste heavily regardless.