UV Dose Calculator

Plan disinfection performance with clear engineering inputs. Assess dose delivery with distance, aging, and transmission. Make faster validation decisions with traceable results and graphs.

Calculator Inputs

Use the engineering correction factors to model real delivery instead of relying only on the lamp’s nameplate irradiance.

Measured or rated irradiance before corrections.
The calculator converts everything to mW/cm².
Informational field for UVC, UVB, or UVA setups.
This is the active exposure duration.
Required time is always reported in seconds.
Enter the minimum dose required by your process.
Used to estimate total delivered UV energy.
The calculator converts area to cm² internally.
Pulsed mode applies a duty-cycle correction.
Use 100% for continuous output.
Distance where irradiance was measured or rated.
Distance used during treatment.
Window, sleeve, or medium transmission percentage.
Accounts for reflection, orientation, and coverage effects.
Represents output decline over service life.
Reduces ideal dose for nonuniform exposure fields.
Multiplies the target dose for conservative design.
Disable this when irradiance already reflects the final working distance.

Example Data Table

These sample cases show how corrected irradiance and exposure time change the delivered UV dose.

Scenario Effective Irradiance (mW/cm²) Exposure Time (s) Dose (mJ/cm²) Design Target (mJ/cm²) Status
Quartz sleeve reactor 2.8000 12 33.6000 30.0000 Target achieved
Conveyor surface line 1.9000 20 38.0000 35.0000 Target achieved
Shadowed enclosure 0.8500 30 25.5000 28.0000 Below design target
Pulsed chamber test 3.4000 8 27.2000 25.0000 Target achieved

Formula Used

1) Irradiance conversion
Convert all source values to mW/cm².
2) Distance correction
Distance Factor = (Reference Distance ÷ Actual Distance)2
3) Effective irradiance
Effective Irradiance = Base Irradiance × Distance Factor × Transmission × Geometry × Aging × Uniformity × Duty Multiplier
4) Delivered dose
Dose = Effective Irradiance × Exposure Time
5) Design target
Design Target Dose = User Target Dose × Safety Factor
6) Required time
Required Time = Design Target Dose ÷ Effective Irradiance
7) Total UV energy on area
Total Energy (J) = Dose (mJ/cm²) × Area (cm²) ÷ 1000

Because 1 mW = 1 mJ/s, multiplying mW/cm² by seconds directly yields mJ/cm².

How to Use This Calculator

  1. Enter the lamp or sensor irradiance and choose the matching unit.
  2. Set exposure time and choose seconds, minutes, or hours.
  3. Add the required target dose for your application.
  4. Enter treated area if you want total energy estimation.
  5. Set reference and actual distances, then keep distance correction enabled when appropriate.
  6. Apply transmission, geometry, aging, and uniformity percentages based on measured or design assumptions.
  7. Choose pulsed mode and enter duty cycle when the source is not continuously on.
  8. Apply a safety factor for conservative design review.
  9. Press Calculate UV Dose to show the result above the form.
  10. Use the CSV or PDF buttons to export the calculated summary.

Frequently Asked Questions

1) What does UV dose mean?

UV dose is the total radiant energy delivered to a surface or medium. It equals corrected irradiance multiplied by active exposure time and is usually reported in mJ/cm².

2) Why is effective irradiance lower than lamp irradiance?

Real systems lose output through distance, sleeve transmission, lamp aging, geometry, nonuniform fields, and pulsed duty cycle. Effective irradiance captures these practical reductions.

3) When should I use inverse-square correction?

Use it when your irradiance value was measured at one distance but treatment occurs at another. Disable it when the entered irradiance already represents the final working distance.

4) What safety factor is reasonable?

Many engineering checks use factors from 1.1 to 1.5, depending on uncertainty, fouling risk, sensor confidence, and process criticality. Higher uncertainty usually needs a higher factor.

5) How does pulsed operation affect dose?

If the source is on only part of each cycle, average delivered dose drops proportionally. The calculator applies duty cycle as a multiplier to effective irradiance.

6) Can this be used for air, water, and surface systems?

Yes. The math is general, but the correction factors and target dose should reflect the actual application, organism, surface geometry, and validation method.

7) What is the difference between target dose and design target dose?

Target dose is the minimum required process value. Design target dose adds a safety factor, making the calculation more conservative for engineering decisions.

8) Why does the graph matter?

The Plotly graph helps you see how quickly dose accumulates and whether the chosen exposure time reaches the design target with enough operating margin.

This calculator supports screening and engineering estimation. For validated disinfection design, use calibrated radiometry and application-specific performance testing.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.