Resin Exposure Time Calculator
Estimate base and bottom layer cure times for MSLA and DLP resin 3D printers.
Enter UV power, layer thickness, and resin type to get starting exposure settings.
Resin 3D printing cures liquid photopolymer layer by layer using UV light. Getting the exposure time right is critical: too little and layers do not cure fully (delamination, failed prints). Too much and fine details bleed into each other, dimensional accuracy suffers, and FEP/nFEP film degrades faster.
The Jacobs working curve. Cure depth is approximately:
cure_depth = Dp x ln(E / Ec)
where Dp is the penetration depth of the resin (a material constant), E is the UV exposure dose (mJ/cm²), and Ec is the critical exposure dose (minimum to initiate cure). This is useful for calibration but requires knowing resin-specific constants.
Simpler practical model. Most MSLA printers (Elegoo, Anycubic, Creality Halot, Bambu Photon) have UV irradiance in the range of 2-8 mW/cm². The exposure dose needed for a 0.05 mm layer of standard ABS-like resin is roughly 20-40 mJ/cm². So at 4 mW/cm², you need 5-10 seconds per layer.
Bottom layers. The first 3-8 layers need longer exposure (typically 3-6× normal time) to ensure the print bonds firmly to the build plate. Under-exposed bottom layers are the leading cause of print failure in MSLA printing.
Calibration tools. The RERF (Resin Exposure Range Finder) and Ameralabs Town models are printed specifically to let you dial in exposure in a single test print. These are far more reliable than calculator estimates. Use this calculator for a starting point only, then refine with a calibration print.
Water-washable vs standard resins. Water-washable resins generally need 10-20% less exposure time than standard resins for the same layer thickness.