How much resin should I pour into the vat?

Fill the vat to the maximum fill line marked on the vat, or to about 1/3 of the vat depth. You need enough resin to maintain a minimum level (typically 5-10mm) above the FEP throughout the print as resin is consumed.

What happens if the resin level drops too low?

If resin runs out during printing, the build plate will press into the FEP film without enough resin to form a layer. This causes the print to fail, can damage the FEP, and may leave cured resin stuck to the film.

Can I add resin during a print?

Yes, most printers allow you to pause and add resin. Add slowly and avoid disturbing the FEP or splashing onto the LCD screen. Some printers have auto-refill systems that top up the vat automatically.

Should I overfill the vat?

No. Overfilling can cause resin to spill over the edge when the build plate descends, potentially damaging the LCD screen and making a mess. Always stay below the maximum fill line.

3DPrintCalcs

Resin Tank Calculator — How Much Resin to Pour

Calculate how much resin to pour into your vat for a given print job.

Vat Length

Internal dimension

Vat Width

Model Volume

Support Volume

Min Resin Level

Min depth above FEP

How We Calculate This

Resin Tank Calculations

Vat area = Length x Width (mm²)
Resin for level = Vat area x Min resin height / 1000 (ml)
Resin for print = Model volume + Support volume
Total needed = Level resin + Print resin

The minimum resin level ensures the build plate can submerge fully and resin flows back over the FEP between layers. The print consumes resin from the vat, so the starting volume must account for both.

Frequently Asked Questions

Related Calculators

Resin Volume Calculator

Estimate how much resin a print will consume based on model volume and supports.

Exposure Time Calculator

Calculate layer exposure time based on resin type, layer height and UV power.

Resin Cost Calculator

Work out the resin cost per print based on volume used and bottle price.

Vat Life Calculator

Estimate how many print hours remain before your FEP film needs replacing.

UV Curing Calculator

Calculate post-cure time based on UV wavelength, power and part thickness.

Last updated: February 2026

All calculations are estimates. Always verify settings with test prints before committing to final prints.