How do you calculate total UV energy for a cure?

Multiply the cure area by the target dose to get theoretical energy, then divide by optical coverage efficiency. For 500 cm² at 1200 mJ/cm² and 85% efficiency, theoretical energy is 600,000 mJ and required delivered energy is about 705,882 mJ.

What is UV dose versus UV energy?

Dose is energy per unit area (mJ/cm²) and is what the formulation actually specifies for cure. Total UV energy (mJ) is dose multiplied by the area being cured, so a large part at a modest dose can still demand a lot of total energy.

What is a good optical coverage efficiency?

Well-focused elliptical reflector systems commonly land in the 70-90% range at the part; diffuse or poorly aligned setups can drop below 60%. The 85% default represents a reasonably tuned system with clean reflectors.

Why divide by efficiency instead of multiplying?

Because you need the lamp to emit more than the part absorbs. Dividing 600,000 mJ by 0.85 gives 705,882 mJ, meaning roughly 105,882 mJ is the allowance that is lost to reflector, geometry, and coverage inefficiency.

How does dose relate to line speed?

Dose equals irradiance multiplied by exposure time, and exposure time falls as line speed rises. If you cannot deliver the target dose at your desired speed, you either slow the line, add lamps, or raise lamp power.

What happens if I under-deliver UV energy?

The coating cures incompletely: you get surface tack, poor chemical and abrasion resistance, weak adhesion, and unreacted monomer that can migrate. Overcure is also a risk and causes yellowing and brittleness, so hitting the spec matters in both directions.

UV Curing calculator

UV Cure Area Energy Calculator

UV Cure Area Energy tells you how much total ultraviolet energy, in millijoules, a lamp or LED array must deliver to fully cure a given surface at a specified dose. Process engineers running UV coating, ink, and adhesive lines use it to size lamps, set line speeds, and confirm that a formulation's cure-dose spec is actually being met at the substrate. Because real optics never focus 100% of emitted energy onto the part, the calculator scales the theoretical energy up by a coverage efficiency so you plan for what the lamp must emit, not just what the part needs to absorb. Getting this right prevents undercure (tack, poor adhesion) and overcure (yellowing, embrittlement).

What this calculator does

Convert UV dose and cured area into total UV energy delivered to a coating, ink film, adhesive pattern, or resin surface.
Use it when scaling from lab coupons to production parts, comparing flood-cure area coverage, or estimating the total energy demand of a large coated surface.
It computes the total delivered UV energy in millijoules required to hit a target dose over a defined cure area, adjusted for optical coverage losses.

Formula used

Theoretical energy (mJ) = cure area × dose target
Required delivered energy (mJ) = theoretical energy ÷ optical coverage efficiency

Inputs explained

Cured surface area per pass:
Target UV dose for full cure:
Optical coverage efficiency:

How to use the result

Use it when qualifying a new UV-curable coating or ink, sizing a lamp for a fixed part footprint, or verifying that current lamp output can meet the formulation's cure-dose spec.
It assumes uniform dose across the whole area and a single efficiency figure; it does not account for shadowing on 3D geometry, spectral mismatch between lamp and photoinitiator, or oxygen inhibition at the surface.

Common questions

How do you calculate total UV energy for a cure? Multiply the cure area by the target dose to get theoretical energy, then divide by optical coverage efficiency. For 500 cm² at 1200 mJ/cm² and 85% efficiency, theoretical energy is 600,000 mJ and required delivered energy is about 705,882 mJ.
What is UV dose versus UV energy? Dose is energy per unit area (mJ/cm²) and is what the formulation actually specifies for cure. Total UV energy (mJ) is dose multiplied by the area being cured, so a large part at a modest dose can still demand a lot of total energy.
What is a good optical coverage efficiency? Well-focused elliptical reflector systems commonly land in the 70-90% range at the part; diffuse or poorly aligned setups can drop below 60%. The 85% default represents a reasonably tuned system with clean reflectors.
Why divide by efficiency instead of multiplying? Because you need the lamp to emit more than the part absorbs. Dividing 600,000 mJ by 0.85 gives 705,882 mJ, meaning roughly 105,882 mJ is the allowance that is lost to reflector, geometry, and coverage inefficiency.
How does dose relate to line speed? Dose equals irradiance multiplied by exposure time, and exposure time falls as line speed rises. If you cannot deliver the target dose at your desired speed, you either slow the line, add lamps, or raise lamp power.

Last reviewed 2026-05-12.