Multi-Colour Print Calculator — Filament & Waste

A purge tower (or wipe tower) is a small block printed alongside your model during colour changes. It purges the old colour from the nozzle before printing the new colour, ensuring clean transitions.

Each colour change typically purges around 0.1–0.25 cm³ (100–250 mm³) of filament. PrusaSlicer’s default is about 0.14 cm³ (140 mm³) per change, rising to roughly 0.25 cm³ for a strong transition such as black to white. With hundreds of colour changes this still adds up to significant waste — sometimes 30-50% of the total filament used on heavily multi-coloured prints.

Reduce waste by minimising colour changes per layer, using a purge bucket instead of a tower, printing purge into infill of another model, or using transition settings in your slicer to reduce purge volume.

Purge volume is converted to grams using the density of the material you select: PLA 1.24, PETG 1.27, ABS 1.04, ASA 1.07, TPU 1.21, Nylon 1.14 and Polycarbonate 1.20 g/cm³ (manufacturer technical data sheets). Choosing the right material matters because ABS and ASA are roughly 16% lighter than PLA for the same purge volume.