3D Print Cost

What a print costs is filament plus electricity plus waste — and the electricity is the term people leave out.

At $0.15/kWh a printer averaging 120 W costs about $0.018 an hour to run. That is a rounding error on a two-hour print and about $0.86 on a 48-hour one. On long prints in cheap filament, power approaches the material cost.

Density is doing real work

Filament is sold by weight, but a model has a volume. ABS at 1.04 g/cm³ and PETG at 1.27 mean the same object weighs 22% more in PETG — so it costs 22% more at the same price per kilo. Comparing materials on $/kg alone hides that entirely.

Material cost is a floor, not a price

If you are selling prints, this number is where the calculation starts. Machine depreciation, failed prints beyond the usual allowance, post-processing time and your own labor all sit on top.

A common workshop rule is material × 3 as a minimum, and even that undercharges for anything with supports to remove — support removal is hand work, and hand work is the expensive part of small-batch manufacturing.

The waste allowance is not padding

Purge lines, skirts, brims, supports and the occasional failure. Five percent is what an experienced operator adds to a print they have already dialled in. The first attempt at a new model is much worse than that, and pricing a one-off from the successful print's numbers ignores the two that failed first.

Where the numbers come from

Densities are manufacturer figures. Filament length is computed from the 1.75 mm cross-section, which is why the length figure and the weight figure always agree — they are the same number expressed twice.