Converter Inputs
Use absorbed dose and a radiation weighting factor to estimate equivalent dose.
Formula Used
Equivalent dose estimates biological effect using a radiation weighting factor.
- H is equivalent dose in sievert (Sv).
- D is absorbed dose in gray (Gy).
- wR is the radiation weighting factor (dimensionless).
This tool applies unit conversions, then multiplies by wR.
How to Use This Calculator
- Enter the absorbed dose value from measurement or simulation.
- Select the absorbed dose unit, such as Gy or mGy.
- Choose the radiation type to apply a typical weighting factor.
- For special cases, select “Custom” and enter your wR.
- Click Calculate to view results above the form.
- Use Download CSV or Download PDF for reporting.
Example Data Table
| Absorbed dose | Unit | Radiation type | wR | Equivalent dose (Sv) |
|---|---|---|---|---|
| 0.02 | Gy | Photons (X, gamma) | 1 | 0.02 |
| 50 | mGy | Neutrons (fast) | 10 | 0.50 |
| 120 | µGy | Alphas | 20 | 0.0024 |
| 5 | rad | Protons | 2 | 0.10 |
Examples are illustrative. Use your project’s approved factors.
This guide shows how the converter turns absorbed dose into equivalent dose for clear, consistent reporting across radiation types and units.
1) Why Convert Absorbed to Equivalent Dose
Absorbed dose (gray) measures energy deposited per kilogram, but different radiations can produce different biological effects for the same energy. Equivalent dose applies a radiation weighting factor (wR) to express dose in sievert, allowing direct comparisons across photons, betas, neutrons, and alphas.
2) Units You Will See in Practice
The converter accepts Gy, mGy, µGy, and rad. The rad is an older unit where 1 Gy equals 100 rad. Output is shown in Sv, mSv, and µSv, plus rem where 1 Sv equals 100 rem, supporting consistent documentation.
3) Radiation Weighting Factors at a Glance
The weighting factor wR is dimensionless. Typical values are 1 for photons and electrons, around 2 for protons, higher values for neutrons depending on energy, and 20 for alpha particles and many heavy ions. Use Custom when your procedure specifies a different factor.
4) The Relationship Used by This Converter
The calculation is H = D × wR. First, absorbed dose is converted to gray. Next, wR is applied. Finally, the result is scaled into mSv and µSv and formatted using your selected precision, so identical inputs always give reproducible outputs.
5) Reading mSv and µSv Outputs
Many practical doses are far below one sievert, so scaled units improve readability. For example, 0.0008 Sv becomes 0.8 mSv. Displaying three scales together reduces transcription mistakes when moving between reports, logs, and spreadsheets.
6) What Data Should Be Stored with the Result
Record the absorbed value, unit, radiation type, and the exact wR used. If a custom factor is applied, note the source method or internal procedure. This makes peer review easier and lets others reproduce the same equivalent dose without guesswork.
7) Worked Example with Fast Neutrons
If an estimate is 50 mGy and the field is modeled as fast neutrons with wR = 10, convert 50 mGy to 0.05 Gy and multiply: H = 0.05 × 10 = 0.5 Sv. The tool also reports 500 mSv and 50,000 µSv.
8) Common Pitfalls and Quick Checks
Confirm the absorbed unit before calculating, especially when switching between Gy and mGy. Avoid mixing factors from different standards unless your project allows it. For a simple check, select photons where wR = 1; then Sv should match Gy after conversion.
FAQs
1) What is the difference between absorbed dose and equivalent dose?
Absorbed dose (Gy) describes energy deposited in material. Equivalent dose (Sv) adjusts absorbed dose using a radiation weighting factor (wR) to reflect differences in biological effectiveness across radiation types.
2) What is a radiation weighting factor (wR)?
wR is a dimensionless multiplier applied to absorbed dose. It provides a standardized way to compare the relative biological impact of photons, electrons, neutrons, alphas, and heavy ions.
3) Why does the tool support rad and rem?
Rad and rem are legacy units still found in older reports. The converter includes them to help you translate historical data into SI units and keep records consistent.
4) How do I convert rad to gray?
Use 1 Gy = 100 rad. The calculator applies this automatically when you select rad, then continues the equivalent dose calculation using the chosen weighting factor.
5) When should I use the Custom wR option?
Use Custom when your radiation field is characterized by a specific study, energy spectrum, or internal standard that requires a factor different from the preset options.
6) Why are mSv and µSv shown together?
Scaling helps readability. Many results are small in Sv, so mSv and µSv reduce decimals and make it easier to copy values into forms, logs, and datasets without errors.
7) Can the absorbed dose be negative?
No. Physical absorbed dose is non‑negative. If you have a signed value from a fitting routine or baseline correction, use the magnitude after resolving the measurement method.