STL Calculator: Get the Part Cost Straight From the File
Stop guessing grams. Drop in an STL, 3MF or G-code and see the real volume and cost in seconds — all inside your browser.
People coming from filament tend to price resin the same way: take the price per litre, divide by part volume, done. The result lands well below reality, because resin printing carries a list of costs that FDM simply doesn't have.
What belongs in the math
- Resin — the one item everybody remembers.
- Isopropyl alcohol — it disappears fast, and dirty alcohol has to be replaced.
- FEP film — the clear sheet at the bottom of the vat that UV light passes through. It scratches and clouds; expect 20 to 60 prints depending on part size and care.
- LCD screen — rated in exposure hours. The most expensive consumable and the most forgotten.
- Disposables — gloves, paper towels, filters, scrapers.
- Energy — lower than FDM since there's no hotend or heated bed, but not zero.
- Failures — costlier in resin: a lost part takes the alcohol, the washing time and sometimes the FEP with it.
- Your time — washing, curing, support removal and sanding. In resin, post-processing isn't optional.
The FEP cost per print
Simple math: film price divided by how many prints it survives. A film at $9 lasting 40 prints adds a bit over $0.20 per part. Feels negligible — until you multiply by a hundred parts a month and realise it paid for another film and then some.
The LCD is the silent cost
Unlike the FEP, the screen never warns you. It loses uniformity gradually, and you only notice when parts start failing in one corner of the plate. That's why it belongs in machine depreciation per hour rather than per-part cost.
Resin or filament: which is more profitable?
Per part, filament is cheaper: material goes further and there are no extra consumables. But resin delivers detail FDM can't reach — and that's where the margin lives. Miniatures, jewellery and fine-fit prototypes sell at multiples of cost precisely because FDM can't make them.
Filament wins on volume; resin wins on value.
How to actually spend less
- Hollow the model before slicing, with drain holes. Easiest saving available.
- Fill the plate. Resin print time depends on height, not part count — one miniature or eight at the same height takes the same time.
- Filter the resin when pouring it back. Cured debris punctures the FEP and causes failures.
- Reuse alcohol in two stages: a first wash with used alcohol, a final one with clean.
Run the numbers with your own prices: resin calculator. It adds resin, alcohol, FEP, energy, depreciation, failures and labour, and generates a branded PDF quote. Got the file? Drop the STL or 3MF and the volume comes from the geometry: see how to calculate from the file.
Compare resin printers in the printer database or see the top 10 comparison.
