3D Printing Calculators
Multi-Color Flush Volume Estimator
https://www.3dsizing.com/calculators/multi-color-flush/
Estimate only — not firmware, a slicer profile or a shop quote. Confirm on a test print.
Multi-Color Flush Volume Estimator
Every colour change dumps a tower or a purge line. Multiply swaps by cubic millimetres flushed, then convert that blob to grams and metres so the leftover spool estimate stays honest.
Inputs
Results
- Waste volume
- 16,000mm³
- Waste mass
- 19.84g
- Waste length
- 6.65m
- Extra plastic (cost driver)
- 19.84g
Same as waste mass. Multiply by filament price per gram for the purge line on the invoice.
Recommended gear
PLA 1 kg
Purge is real kilograms over a month of AMS prints. Price the waste at the spool you actually load.
Typical range: $15–$30
AMS-class printer
Flush volume is a profile choice. Faster printers do not make purge free.
Typical range: $300–$1,500
PETG 1 kg
PETG is denser than PLA, so the same cubic millimetres weigh more.
Typical range: $18–$35
Calculation method
Total waste volume is colour-change count times flush cubic millimetres per change. Mass in grams is (mm³ / 1000) × density g/cm³ because 1000 mm³ is 1 cm³. Length in metres uses the same cylinder as remaining filament: grams per metre = π (d/2)² × density. The extra-cost output repeats waste grams so a shop can multiply by price per gram. Densities match the length-to-weight converter.
Exact formula
waste_mm³ = colour_changes × flush_mm³. waste_g = (waste_mm³ / 1000) × density. Metres from mass like remaining filament. extraCostMultiplier echoes waste_g so you can multiply by price per gram. Limits: Prime-tower millilitres are extra unless you folded them into flush_mm³. Densities are neat-polymer averages.
Tool-change count vs colours
A four-colour model can still have 200 swaps if the slicer paints every layer. Use the slicer’s change count, not the AMS slot count.
Frequently asked questions
Where do I read flush mm³?
In Bambu Studio it is the flush volume matrix. On Prusa MMU it is related to the purge line. If you only know millimetres of filament, convert with the length-to-weight tool first.
Is a prime tower included?
Only if you folded that volume into flush per change. A separate tower is extra millimetres the slicer already counted as part mass.
Why is PETG heavier for the same flush?
Higher density. 400 mm³ of PETG is more grams than 400 mm³ of ABS.
Can I cut waste by lowering flush?
Yes until colours smear. Dark-into-light needs more than light-into-dark. This calculator does not pick a safe flush — it only prices the one you typed.
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