3D Printing Cost Methodology: Line by Line

Direct costs

Material = grams consumed × (spool price ÷ spool weight). Consumed includes supports and purge.

Energy = (average power in kW) × print hours × rate per kWh.

Machine = print hours × machine cost/hour, where cost/hour = (machine price ÷ estimated useful life in hours) + expected maintenance.

Labor = minutes of human work × the value of your minute. Prep and post-processing, not the time the machine runs unattended.

Overhead and allocation

Overhead = monthly fixed costs ÷ productive hours in the month × hours for this piece. It's rent, internet, software. A rough, explicit allocation beats pretending they don't exist.

Markup, fees, and taxes — in this order

Subtotal = direct + overhead, and that is what we call the cost. Base price = subtotal × (1 + markup) — markup is what you add on top of the cost; margin is the slice of the price left after paying it. The final price only exists after fees and taxes.

Platform and payment fees apply to the price, not the cost — that's why they come after markup. Applying them earlier underestimates how much you need to charge.

Sales tax closes out the math, also applied to the price, based on your tax situation.

Failure: the line nobody accounts for

An 8% failure rate is a 92% success rate: for 100 sellable pieces you printed 100 ÷ 0.92 ≈ 109. If those 9 lost attempts aren't accounted for somewhere in the price, they're coming out of your pocket.

How to measure each layer in practice is in how to calculate the cost of a 3D print; how to turn that cost into a selling price is in how much to charge for 3D printing.