Filament Swap Calculator — Multi-Colour Purge Waste
Calculate purge waste and time added when swapping filament colours mid-print.
Number of filament swaps in the print
Length of purge line per swap
Nozzle size fitted to your printer
Layer height used for the print
Cost per kilogram of filament
Seconds to complete each filament swap
Print time without swap delays
How We Calculate This
Formula
- Waste per swap = Purge length x line cross-section x material density
- Total waste = Waste per swap x Number of colour changes
- Waste cost = Total waste (kg) x Filament cost per kg
- Added time = Swap time per change x Number of changes
The purge line cross-section is calculated from nozzle diameter, layer height and an extrusion width factor.
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: March 2026
All calculations are estimates. Always verify settings with test prints before committing to final prints.