How to work out the cost of a 3D print
- Click Open an STL, or drop the STL on the part. The page opens with a sample bracket, so the figures show before you open a file.
- Check the size beside the part. An STL holds no units, so choose Inches if the part looks 25.4 times too small.
- Choose the process and the material, then the print settings your slicer uses: layer height, line width, walls, top and bottom layers, infill and average speed.
- Replace the example prices with your own: the price per kilogram, the machine rate, the electricity price and the labour rate. Each example price carries an Example tag until you change it.
- If you have sliced the part, type the slicer's material and print time under From your slicer. The slicer's figures replace the estimates.
- Click Copy results to paste the estimate into a quote, or Download CSV.
How the calculator estimates material and time
The calculator adds up the volume that the STL's triangles enclose, then estimates how much of that volume the printer fills. A slicer prints the outside of a part solid and fills the inside with a sparse pattern. In PrusaSlicer's terms, perimeters form the walls, solid layers close the top and the bottom, and infill supports the top layers from inside.
Shell = wall area × walls × line width + flat area × top and bottom layers × layer height
Material = (shell + infill % × (volume − shell)) × (1 + supports and waste %)
Print time = material ÷ (layer height × line width × average speed)
Cost per part = (material + machine time + electricity + labour) ÷ (1 − failed prints %)
The flat area is the area of the faces within 45 degrees of horizontal, which get top and bottom layers. The wall area is the rest. The shell never counts for more than the volume, so a thin part comes out solid. The weight is the volume of material times the density. The densities in the material list come from the generic material profiles that UltiMaker Cura ships, from 1.06 g/cm³ for ASA to 1.27 g/cm³ for PETG.
For resin, the calculator counts layers: the print time is the height of the part divided by the layer height, times the time per layer that you enter. The resin used is the volume of the part plus the allowance for supports and waste.
A worked example: the sample bracket
The sample is an L bracket 60 by 40 by 45 mm, 5 mm thick, with four 6.5 mm holes. The STL encloses 23.34 cm³. With the example settings for PLA, 2 walls, 4 top and bottom layers and 20% infill, the calculator returns these figures.
| Line | Result |
|---|---|
| Volume of the part | 23.34 cm³ |
| Walls, top and bottom | 9.55 cm³ |
| Infill at 20% of the inside | 2.76 cm³ |
| Material | 15.3 g of PLA, $0.38 |
| Print time | 1 h 31 min at 2.25 mm³/s, $4.56 of machine time |
| Electricity | 0.23 kWh, $0.03 |
| Labour | 10 min, $6.67 |
| Failed prints at 5% | $0.61 |
| Cost per part | $12.25 |
| Price at 50% markup | $18.38 |
The prices are examples: $25.00 a kilogram for filament, $3.00 an hour for the printer, $0.15 a kWh for electricity and $40.00 an hour for 10 minutes of labour. With your own prices the total changes, and so does the share of each line. In this example, labour is 54% of the cost.
What the estimate leaves out
- Units. STL files contain no scale information, so the calculator reads the numbers as millimetres until you choose inches.
- Supports, brims and purge. The calculator does not plan supports, brims or purge lines. Add the material they use as a percentage under Supports and waste, or type the slicer's material figure.
- Travel and slowdowns. The time estimate is the extrusion time at the average speed you enter. A real print also travels between areas and slows down on short moves and on the first layer, so enter the average from past prints, or type the slicer's time.
- Orientation. The split between flat faces and walls follows the part as it sits in the STL. Turning the part on the bed changes the shell, the supports and the time.
- Open meshes. A mesh with gaps encloses no clear volume, so the calculator flags the mesh and the volume may be wrong. Repair the STL, or type the slicer's figures.
Price every printed part from its file
Tell Derik how requests for quote reach your team and how a printed or machined part is priced today. He will tell you what a four-week build would cover.
Start a conversationHow a shop prices a printed part
The cost of a printed part comes from the lines this calculator shows: material by weight, machine time at an hourly rate that pays for the printer and the upkeep, electricity, and labour for setup, removal and finishing. An allowance for failed prints spreads the cost of reprints over the parts that come out. The guide to CNC quoting shows how a shop rate turns machine time into a price, and a printer's rate is built the same way.
The markup then turns the cost into a price. The markup calculator converts a markup into the margin it gives. A shop that quotes printed and machined parts every day repeats these steps for each file in each request. ThriveAI builds quoting systems that read each request, measure each model and draft the quote from the shop's own rates, for an estimator to approve. See AI quoting software.