How to work out what a print costs
- Drop in your STL. It’s read on your device – volume, surface and height come straight from the model.
- Match your slicer settings – infill, walls, top/bottom layers and layer height all change the filament used.
- Pick your filament and printer, then set your prices and currency.
- For a firm quote, type in the grams and minutes your slicer reports. Download the cost sheet as CSV.
How the estimate works
| Part | How it’s worked out |
|---|---|
| Filament | Walls (perimeters × line width) and top/bottom skins (layers × layer height) over the model’s surface, plus infill % of what’s left inside, plus your supports/brim allowance. Checked against PrusaSlicer 2.7: within ±6 %. |
| Print time | Heat-up + plastic ÷ your printer’s effective flow + a few seconds per layer, never faster than tiny layers allow. About ±25 % until calibrated. |
| Electricity | Average power × time × your price per kWh. |
| Machine wear | Time × your per-hour figure (printer price and spare parts spread over its life). |
| Markup | Your margin on top of the subtotal, for selling prints. |
Designing the part too? Every other bench on 3D MakerBench makes print-ready STLs you can drop straight in here – try the Box Bench or the Grid Bench.
Frequently asked questions
How accurate is it?
Filament is worked out from your model’s real shape – walls, top and bottom layers and infill – and lands within about ±6 % of PrusaSlicer on our test shapes. Print time is harder to predict without slicing, so treat it as ±25 % until you calibrate it (see below). For a firm quote, type in the grams and minutes your slicer shows – the calculator then uses those.
How do I make the time estimate match my printer?
Slice any one part, type the slicer’s print time into “Slicer says – minutes”, and the page shows your printer’s effective flow. Put that number into “Effective flow” and clear the slicer box: estimates for other parts will now match your printer much more closely.
Is my file uploaded anywhere?
No. The STL is read by your browser on your own device; nothing is sent to a server.
What is “effective flow”?
The average amount of plastic your printer really lays down per second over a whole print – slow outer walls, small layers and travel included. It is much lower than the top speed on the box: around 3 mm³/s for a classic bed-slinger and 6–10 mm³/s for a modern fast printer.
What does machine wear cover?
A share of the printer’s price and its spare parts (nozzles, belts, build plates) per hour of printing. A $600 printer that lasts 3,000 hours is about $0.20 per hour, plus parts.
My STL is not watertight – does that matter?
The volume of a model with holes in its surface can be wrong, so the filament estimate can be too. Repair it in your slicer or with a mesh-repair tool, or use the grams your slicer reports.