Spoolbay

What does a 3D print really cost?

Type the filament amount and print time from your slicer. I add the filament, the electricity and any allowances you set, so you can see what one print and one part cost.

Filament
g

Density 1.24 g/cm3. Used only when you enter a length.

Used only when you enter a length.

Spool
per spool
g

The filament only, not the empty spool.

Power
W
h
min
$ per kWh
Allowances (optional)
% of prints

Spreads the cost of failed prints over the good ones.

$ per print hour

Nozzles, belts and build sheets wear out. Leave 0.00 to skip.

parts

How the numbers work

Filament is the part most people guess. I take the grams your slicer reports and multiply them by what one gram of that spool cost you: the spool price divided by its net weight. If you only have a length, I turn meters into grams using the filament's diameter and the density of the material.

Electricity is the printer's power draw in watts, times the print time in hours, divided by 1000 to get kWh, times your rate. Wear is your per-hour allowance times the print time. Then I divide the subtotal by (1 minus the failure rate), because a failed print costs about as much as a good one, so the prints that fail are paid for by the ones that work. Divide by the parts on the plate for the cost per part.

Here is the default as a worked example. These are example inputs, so replace them with your own. 42 g of PLA from a $20.00, 1000 g spool is 42 times $0.02, which is $0.84. One printer maker publishes a measured average of 80 W while printing PLA, so 3 hours 30 minutes (3.5 hours) is 0.28 kWh, and at $0.17 per kWh that is $0.05. Together that is $0.89 for the print. Check the power figure in your own printer's manual, because it changes the electricity line more than anything else.

Where the numbers come from

Each density and default listed here is the maker's or the agency's own published figure. I have not measured any of them myself.