Resin Volume Calculator
Estimate how much resin a print will consume from the model volume, support overhead, raft and failure-buffer percentages — plus how much to pour into the vat including the FEP coverage minimum.
Estimate how much photopolymer a resin print will actually use — the model itself, its supports, the raft, and a safety buffer for failures — then see how much to pour into the vat so the FEP film stays covered from the first layer to the last. It's the number you want before every print, so you neither run dry mid-job nor pour half a bottle you'll scrape back into the funnel.
curl -X POST https://toolsamurai.com/api/v1/resin-printing/resin-volume-calculator \ -H "Authorization: Bearer sk_live_•••••••••••••••" \ -H "Content-Type: application/json" \ -d '{ "model_volume_ml": 35, "supports_overhead_pct": 20, "raft_volume_ml": 4, "failure_buffer_pct": 5, "vat_minimum_ml": 100, "resin_density_g_per_ml": 1.1 }'
The method behind the numbers
Support overhead is applied as a percentage of the model volume, because supports scale with the part rather than being a fixed cost. Tree supports for a well-oriented model add roughly 10–25%; dense supports for difficult overhangs can push past 40%. The raft is added as a flat volume since it depends on plate footprint, not part size.
The failure buffer is a percentage on top of the model-plus-supports-plus-raft subtotal — it covers the resin you lose to splash, drips and the occasional partial failure. The vat-pour figure then adds your printer's minimum coverage volume on top of what the print consumes, so the FEP is never starved even on the final layer. Mass is simply volume multiplied by resin density, which is why density is an input: ABS-like and dental resins are denser than standard, and that changes the gram figure used for shipping or cost.
See it in practice
A typical 28 mm scale figure, well oriented, with a small raft on a Saturn-class printer.
- model_volume_ml
- 35
- supports_overhead_pct
- 20
- raft_volume_ml
- 4
- failure_buffer_pct
- 5
- vat_minimum_ml
- 100
- resin_density_g_per_ml
- 1.1
A big, mostly self-supporting print where staged pouring beats one huge fill.
- model_volume_ml
- 300
- supports_overhead_pct
- 25
- raft_volume_ml
- 6
- failure_buffer_pct
- 5
- vat_minimum_ml
- 150
- resin_density_g_per_ml
- 1.15
Frequently asked questions
How do I find my model's volume?
Every slicer reports it. In Chitubox and Lychee the estimated resin volume appears after slicing, usually in millilitres. 1 cm³ equals 1 ml, so a CAD volume in cubic centimetres drops straight in.
Why is the vat pour higher than what the print consumes?
The FEP at the bottom of the vat has to stay submerged for the whole print, otherwise the last layers pull from an exposed film and fail. The pour figure adds your printer's minimum coverage volume to the consumption so the level never drops below that floor.
What support overhead should I use?
Start at 20% for a typical, well-oriented model on tree supports. Lower it toward 10% for chunky parts with few supports, and raise it toward 35–40% for thin, heavily-overhung models that need a dense support cage.
Does resin density actually matter?
It doesn't change the millilitres, but it changes the grams. Standard resins sit around 1.05–1.20 g/ml; ABS-like is heavier and dental heavier still. Use the gram figure when you care about cost-per-kilo or postage weight.
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