Why is total energy not a useful answer?

Because nothing in the process speaks millijoules. Radiometers read mW/cm², datasheets specify mJ/cm², arrays are quoted in watts and lines run at speed.

Why does the irradiance row ignore coverage?

Because coverage happens between source and part, and irradiance is measured at the part. The source power row carries the coverage loss.

Can I trade exposure time for irradiance?

For dose-limited cure, yes. Two limits bite: oxygen inhibition needs high peak intensity, and some chemistries show reciprocity failure at very short exposures.

Should I use footprint or surface area?

Use the developed surface being cured. A shaped part can have two or three times the area of its shadow, and the footprint understates the requirement.

UV Curing calculator

UV Cure Area Dose Calculator: Irradiance and Optical Power

Turn a cured area and a dose target into equipment numbers. Enter the area, target dose, optical coverage and exposure time per pass.

What this calculator does

Convert a cured area and target dose into surface irradiance and the UV optical power the source must deliver.

Formula used

Theoretical energy = cured area × target dose
Delivered energy = theoretical energy ÷ coverage
Coverage allowance = delivered − theoretical
Required irradiance = target dose ÷ exposure time
Optical power = delivered energy ÷ (exposure × 1000)

Inputs explained

Cured Surface Area per Pass: Developed surface cured in one pass.
Target UV Dose for Full Cure: Dose the material needs at its surface.
Optical Coverage Efficiency: Share of emitted UV that lands on the part.
Exposure Time per Pass: Seconds the surface spends under useful irradiance.

How to use the result

Best suited to specifying a lamp from dose and cycle time, testing whether a line speed is achievable, quantifying what poor coverage costs in power.
Real sources fall off at the edges, so irradiance is a minimum not a spec. Says nothing about spectral distribution or reciprocity failure. Treats coverage as one number when it varies across a shaped part.

Common questions

Why is total energy not a useful answer? Because nothing in the process speaks millijoules. Radiometers read mW/cm², datasheets specify mJ/cm², arrays are quoted in watts and lines run at speed.
Why does the irradiance row ignore coverage? Because coverage happens between source and part, and irradiance is measured at the part. The source power row carries the coverage loss.
Can I trade exposure time for irradiance? For dose-limited cure, yes. Two limits bite: oxygen inhibition needs high peak intensity, and some chemistries show reciprocity failure at very short exposures.
Should I use footprint or surface area? Use the developed surface being cured. A shaped part can have two or three times the area of its shadow, and the footprint understates the requirement.

Last reviewed 2026-10-01.