Rand-Conscious 3D Printing: Calculating Filament Cost per Model
Knowing the material cost before pressing print makes an experiment easier to judge. Filament cost per model is a direct calculation from grams and spool price, then a realistic allowance for supports, purge and tests. ELEGOO Galaxy is R399 for 1kg of 1.75mm PLA, so it costs about R0.399 per gram before those additional print costs.
Quick Answer
Multiply the model's grams by the spool price, then divide by 1,000. With 1kg of Galaxy PLA at R399, material costs about R0.399 per gram: a 50g print is R19.95 and a 250g prop is R99.75 before electricity, supports, purge and failed attempts.
🧮 Work the calculation first
The per-gram figure is R399 divided by 1,000g, which equals R0.399. A slicer estimate of 50g multiplied by R0.399 gives R19.95. For a 250g model, 250 times R0.399 gives R99.75. Keep the units visible during the calculation so a kilogram price is not accidentally treated as a gram price.
Use the slicer's filament estimate as a planning figure, not a promise. A brim, support, purge line or failed first layer consumes material beyond the ideal model volume. For a one-off project, add a small test allowance before deciding whether a print fits the budget.
📦 Count what the model actually needs
A 250g display prop may be a R99.75 material estimate, but an unusual orientation can add support or require a failed fit test. A better plan is to print the mating or visible detail section first. If it works, the long print has a stronger chance of matching the estimate.
Galaxy PLA's colour shifts, gloss and visual depth make it worth reserving for the surfaces that will be seen. A hidden prototype can use a different material if that prevents decorative filament being consumed on a fit test.
🧾 Use the number to compare choices
The cost calculation can compare wall counts, infill choices and model sizes. It should not be used to make a thin object unsafe just to save a few rand. First set the strength, fit and visual requirements, then compare sensible variations. A model that fails in use is more expensive than a slightly heavier successful one.
Browse 3D printing filament, and use the current best sellers view after calculating what the project truly needs.
Frequently Asked Questions
Does R0.399 per gram include electricity?
No. It is the material calculation from a R399, 1kg spool. Add electricity, supports, purge and test material separately when those matter to the project.
Why can the slicer estimate differ from the final use?
The estimate may not cover a failed first layer, extra tests or changes to supports and orientation after planning.
Should I reduce walls to lower the rand cost?
Only if the part remains suitable for its job. Define the required strength and fit first, then compare responsible settings.
Ready to turn the slicer's gram estimate into a useful rand decision? Multiply the grams by R0.399, add a test allowance, and reserve the decorative material for the visible final piece.
