FDM Calculator — How to Guide
Step by step guide to calculating your filament costs, electricity, platform fees and finding the right selling price for your FDM prints.
Ready to try it yourself — open the tool →
Your spool cost and weight
Check the price you paid and the spool weight — usually 1kg. Find this on the spool label or your receipt.
How much filament your print uses
Your slicer (Bambu Studio, PrusaSlicer, Cura etc.) shows filament usage in grams or metres before you print.
Your print time
Your slicer estimates this. Enter it in hours — a 4 hour print is 4, a 90 minute print is 1.5.
Your electricity rate
Check your energy bill for your rate per kWh. UK average is around £0.28/kWh. FDM printers typically use 100–300W.
Your packaging costs
Add the cost of boxes, tissue paper, bubble wrap — whatever you use per order.
It calculates your true filament cost
Cost per gram from your spool multiplied by grams used — far more accurate than guessing.
It adds electricity and packaging
FDM printers use more power than resin — electricity adds up on long prints. The calculator accounts for this precisely.
It shows your break-even price
The minimum you can charge to cover all costs including platform fees. Never sell below this.
It recommends a selling price
Use the target margin slider to set the profit you want — the calculator works out what you should charge to hit it.
Ready to calculate your costs?
Enter your filament details and get your true print cost, break-even price and recommended selling price instantly.
Open FDM calculator →