3D PRINTING GUIDE
What does a 3D print
really cost?
Filament is only the first line of the calculation.
THE BASIC FORMULA
Start with the costs you can measure.
Material cost is the easiest part: divide the filament price by the spool weight, then multiply by the grams used by the print. A £20 one-kilogram spool costs £0.02 per gram, so a 100 g part uses about £2 of filament before waste.
Electricity is normally smaller than people expect, but it still belongs in the calculation. Multiply the printer's average power in kilowatts by the print time in hours and by your electricity price per kWh. A printer averaging 150 W for five hours uses about 0.75 kWh.
DON'T FORGET THE PRINTER
Machine time has a cost too.
Nozzle wear, belts, bearings, build surfaces and the printer itself all have finite life. A simple way to account for that is to spread the purchase price over an estimated number of productive printing hours. A £500 printer spread across 5,000 hours contributes £0.10 per printing hour.
For selling prints, also include failed prints, purge and support material, packaging, marketplace fees, payment fees and any hands-on finishing time. These are business costs even when the slicer cannot see them.
PRICE VS COST
Profit margin is not the same as markup.
If a part costs £8 to make and you simply add 25%, the selling price is £10. That is a 25% markup, but only a 20% margin. If you want a 25% margin, divide the cost by 0.75 instead. That gives a selling price of about £10.67.
The right margin depends on the job, competition, design value, customer service and how much risk you carry. The important part is knowing your real cost before choosing a price.