Radiation Dose Converter Calculator

Quick start

Enter a value, choose units, then convert.

You can also enable quality factors and air-kerma links.

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Conversion mode

Within-mode converts only inside the selected quantity.

Input value

Scientific notation like 1.2e-3 is allowed.

Quantity (within-mode)

Disabled when an advanced path is selected.

From unit

To unit

Quality factor (absorbed → equivalent)

Used only in “Absorbed → Equivalent” mode.

w_R (dimensionless)

Typical: photons ≈1, neutrons higher, alpha ≈20.

Air-kerma link (exposure ↔ kerma)

Used only in “Exposure ↔ Air kerma” modes.

Factor (Gy per R)

Default is common for air calibration.

Energy / calibration correction

Keep 1.0 unless you have calibration data.

Example conversions

These examples show typical unit relationships for quick verification.

Sample dataset

Mode	Input	Output	Key factor
Within quantity	1 Gy	100 rad	1 rad = 0.01 Gy
Within quantity	5 mSv	500 mrem	1 rem = 0.01 Sv
Within quantity	1 R	2.58e-4 C/kg	definition of roentgen
Absorbed → Equivalent	0.2 Gy, w_R=2	0.4 Sv	H = D · w_R
Exposure → Air kerma	10 mR	~0.876 mGy (air)	~0.00876 Gy/R

For cross-quantity work, use calibration data whenever possible.

Formula used

Within absorbed dose: 1 rad = 0.01 Gy, so Gy = rad × 0.01.
Within equivalent dose: 1 rem = 0.01 Sv, so Sv = rem × 0.01.
Exposure definition: 1 R = 2.58×10⁻⁴ C/kg.
Absorbed → equivalent: H(Sv) = D(Gy) × w_R.
Exposure ↔ air kerma: K_air(Gy) ≈ X(R) × (Gy/R) × correction.

Tissue weighting and effective dose need additional factors not modeled here.

How to use this calculator

Select a conversion mode that matches your task.
Enter the numeric value, then choose “From” and “To” units.
For absorbed → equivalent, set the quality factor w_R.
For exposure ↔ kerma, keep correction at 1.0 unless known.
Press Convert. The result appears above the form.
Use Download CSV or PDF to save the latest result.

Professional guide: interpreting dose-unit conversions

Use this reference to understand what each quantity represents and how the calculator applies the conversion factors.

Absorbed dose and energy deposition

Absorbed dose measures energy deposited per mass. In SI units, 1 gray equals 1 joule per kilogram. Legacy units still appear: 1 rad equals 0.01 Gy, so 1 Gy equals 100 rad. The calculator converts absorbed-dose units using exact factors. For mGy and µGy, precision stays consistent.

Equivalent dose and quality factors

Equivalent dose scales absorbed dose by radiation effectiveness. The calculator applies H(Sv) = D(Gy) × w_R in absorbed-to-equivalent mode, then converts to rem where 1 rem equals 0.01 Sv. For stability, the w_R input is constrained between 0.01 and 50.

Exposure and charge in air

Exposure describes ionization produced in air and is defined by charge per mass. One roentgen equals 2.58×10⁻⁴ C/kg, built into the unit list. Exposure is historical but can appear in calibration certificates, older survey meters, and legacy shielding documentation.

Air kerma bridge used in this tool

To relate exposure to absorbed-dose-type quantities, a common bridge is air kerma. The tool uses an editable factor near 0.00876 Gy per roentgen in air, multiplied by an optional correction. This pathway helps quick estimates when you have air calibration data.

Common unit scales and prefixes

Radiation levels span many orders of magnitude, so prefixes matter. The interface includes nano, micro, milli, and base units for Gy and Sv, plus mR and mC/kg options. Example: 10 mR equals 0.01 R, 2.5 mGy equals 0.0025 Gy, and 250 µSv equals 0.25 mSv.

Typical reference values for context

Background effective dose is often a few millisieverts per year, while many diagnostic CT exams fall in the single‑digit millisievert range. Occupational limits and facility action levels vary, so treat these figures as context, not compliance guidance.

Reporting and auditing with exports

After a successful conversion, CSV and PDF exports capture timestamp, mode, input, output, base value, and notes. This supports QA checks, lab notebooks, and training exercises without manual transcription errors, especially when repeating many conversions.

Practical workflow for safe conversions

Choose the quantity you actually measured: absorbed dose, equivalent dose, or exposure. Convert within that family whenever possible. Use cross‑quantity modes only when you can justify w_R or the air‑kerma factor from calibration. Export results to preserve assumptions.

FAQs

1) What is the difference between Gy and Sv?

Gy measures absorbed energy per kilogram. Sv applies biological weighting, typically H = D × w_R, so it depends on radiation type and assumptions.

2) When should I use rem instead of Sv?

Use rem when working with legacy reports or instruments. The conversion is exact: 1 rem = 0.01 Sv, and 1 mrem = 1e−5 Sv.

3) What quality factor should I enter for w_R?

Enter the value from your protocol or calibration notes. Photons/electrons are often 1, alpha is often ~20, and neutrons vary by energy. If unsure, avoid cross‑quantity conversion.

4) Why is exposure-to-kerma marked as an estimate?

Exposure and kerma depend on beam quality and calibration in air. The Gy/R factor is a typical air value and may differ for your energy spectrum, filtration, or chamber response.

5) How do the CSV and PDF downloads work?

Run a conversion, then click Download CSV or Download PDF. Exports include timestamp, mode, input, output, base value, and notes from the latest successful calculation.

6) Does the calculator handle metric prefixes automatically?

Yes. Select the correct unit (µSv, mSv, mGy, etc.) and the tool applies the scale factor. Double‑check that your instrument reading matches the chosen prefix.

7) Does this compute effective dose in Sv?

No. Effective dose requires tissue weighting and irradiation geometry. This tool converts units and can apply a quality factor, but it does not model organ doses or ICRP weighting.