AMS Purge Waste Calculator
Multi-colour prints flush filament at every colour change. Enter the numbers from your slicer to see the real waste in grams and money.
Estimates only. Check numbers against your own slicer, scale and electricity bill. Some links on this page may be affiliate links.
Formula
Flush grams = colour changes × flush volume (mm³) ÷ 1000 × density. Total = model + flush + prime tower. Cost = total ÷ 1000 × price per kg. Example: 40 changes × 150 mm³ = 6 cm³ × 1.24 = 7.44 g of flush; with a 26 g model and 5 g tower that is 38.44 g, about $0.77 at $20/kg, and 32% of it is waste.
Where to find the numbers
Bambu Studio and OrcaSlicer show the number of filament changes and flushed grams in the slice preview summary, and per-pair flush volumes under Flushing volumes. Dark-to-light changes need much bigger flushes than light-to-dark.
How to waste less
- Lower the flushing volume multiplier and test (many users run 0.6–0.8 safely for similar colours).
- Enable flush into infill or flush into object so purge goes into parts you can't see.
- Print several copies on one plate — the colour changes are shared between them.
- Order colours light to dark and reduce the number of colour layers.
Method: flush volume → grams via density, as used by common multi-colour calculators. Your slicer's own flush grams are the best input when available.
Related: full print cost · filament length ↔ weight
FAQ
Why does my AMS waste so much filament?
Each colour change pushes old filament out of the hotend until the new colour runs clean. With many layers and colours this can add up to more filament than the model itself.
What flush volume should I use?
Start with your slicer defaults (often 100–700 mm³ depending on colours) and reduce the multiplier in small steps while checking for colour bleed.
Does a prime tower count as waste?
Yes, unless you print something useful in it. Include its weight in the tower field.