Calculator
What the Absorbed Dose Converter does
Absorbed Dose Converter: 1 Gy = 100 rad, so multiply a gray value by 100 to get rad, or divide to go back. Example: 1 Gy = 100 rad.
The inputs are Value, From and To; the output is Result, How it was calculated and Reverse conversion. Change any input and the output follows immediately.
Unit mistakes are quietly expensive. They have wrecked spacecraft and ruined recipes alike. That is usually what brings students converting units for homework here.
The work is done by JavaScript already loaded in your browser, so your input never crosses the network.
The field reference, the method and a worked example using the default inputs follow the tool itself.
What do the Absorbed Dose Converter fields mean?
The Absorbed Dose Converter uses 3 inputs. Because the form arrives filled, the first useful result costs you zero typing.
| Field | What to enter | Default |
|---|---|---|
| Value | required | 1 |
| From | choose from Gray (Gy), Milligray (mGy), Microgray (µGy), Rad (rad) or Millirad (mrad) | Gray (Gy) |
| To | choose from Gray (Gy), Milligray (mGy), Microgray (µGy), Rad (rad) or Millirad (mrad) | Rad (rad) |
How does the Absorbed Dose Converter work?
Both units are converted through absorbed dose's base unit (Gy), so any of the 5 units in the dropdowns can be paired in either direction without loss of accuracy.
Where a unit has an exact legal definition, that exact value is used rather than a rounded one. The 1959 international agreement fixing the inch at 25.4 mm is the best-known example; the same principle applies throughout.
Worked example
These are the values the Absorbed Dose Converter loads by default, and the result it produces from them. Open the tool above and you will find precisely these figures already in place.
| Value | 1 |
|---|---|
| From | Gray (Gy) |
| To | Rad (rad) |
| Result | 100 rad |
|---|---|
| How it was calculated | 1 Gy = 100 rad, so 1 × 100 = 100 rad |
| Reverse conversion | 0.01 Gy (if you meant 1 rad) |
Absorbed radiation dose
1 gray (Gy), the SI unit of absorbed radiation dose, equals exactly 100 rad, the older unit it replaced, both measure the amount of radiation energy actually absorbed per kilogram of material or tissue, regardless of the type of radiation involved.
Worth knowing
- Absorbed dose (gray/rad) measures a purely physical quantity (energy deposited per unit mass), and is distinct from equivalent dose (sievert/rem), which additionally weights that energy by how biologically damaging the specific type of radiation is.
- A typical chest X-ray delivers an absorbed dose on the order of a fraction of a milligray, while radiation therapy for cancer treatment can deliver tens of gray to a targeted area: an enormous range reflecting how differently these two applications use ionising radiation.
- The rad, still occasionally seen in older US medical and regulatory records, converts to gray at a clean factor of 100, making conversions between the two unusually straightforward compared with most of the historical-unit conversions elsewhere on this site.
Definitions: BIPM SI Brochure · NIST reference on units
How to use it
- Key in Value.
- Pick a value for From: the options are Gray (Gy), Milligray (mGy), Microgray (µGy), Rad (rad) or Millirad (mrad).
- Pick a value for To: the options are Gray (Gy), Milligray (mGy), Microgray (µGy), Rad (rad) or Millirad (mrad).
- There is nothing to click. The answer keeps pace with your edits.
- Read Result, How it was calculated and Reverse conversion in the results panel.
- Use Copy Link if you want the same setup again later, or Print for a paper copy.
What this tool does not do
- Factors use the internationally agreed definitions; some industries round them differently.
- Repeated conversions compound rounding, so convert once from the original value where you can.
- Precision beyond what the inputs justify is not meaningful, however many digits appear.
- A plausible-looking answer from the wrong input is still the wrong answer: verify the fields first.
Frequently asked questions
Value, From and To. That is the whole form. Each field is pre-filled with a sensible default, so you can change one value at a time and watch how the result responds.
With the values loaded when the page opens, result comes out as 100 rad. Nudge one field at a time to see which one the answer is most sensitive to.
Not at all: the whole thing runs offline once the page has loaded, which tells you nothing is being sent.
Free for any use, personal or commercial.
It follows the standard definition for this operation, so the result matches what a reference implementation would give.