Hectogray is 100 gray units.
Hectograys to Rads Converter — hGy to rad
Convert Hectogray (hGy) to Rad (rad) using the exact conversion factor (1 hectogray = 10,000 rad). See the formula, worked examples, conversion table, and common uses.
Hectograys to Rads converter
Converter
Radiation Converter
Convert radioactivity, absorbed dose, and equivalent dose units by compatible radiation family.
Context values
Some unit families need one extra value for a physically accurate result.
Rad is 0.01 gray.
Result = input x 100 / 0.01.
Absorbed Dose units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Hectograys to Rads
Hectogray and Rad both belong to the radiation-measurement family, though radiation quantities fall into genuinely distinct categories: absorbed dose (gray, rad) measures energy deposited in matter, equivalent dose (sievert, rem) weights that for biological harm, and activity (becquerel, curie) measures how often a radioactive source decays — this page only converts between units of the same kind. Specifically: Hectogray is 100 gray units, and rad is 0.01 gray.
Formula
rads = hectograys × 10000
This factor comes from each unit's defined relationship to the category's base unit: 1 hectogray equals 100 base units, and 1 rad equals 0.01 base units, so dividing one by the other gives the direct hectogray-to-rad factor of 10000.
Simple example
1 hGy × 10000 = 10,000 rad
1 hectogray = 10,000 rads.
Real-world example
10 hGy × 10000 = 100,000 rad
10 hectograys = 100,000 rads.
Conversion table
| Hectogray (hGy) | Rad (rad) |
|---|---|
| 0.001 hGy | 10 rad |
| 0.01 hGy | 100 rad |
| 0.1 hGy | 1,000 rad |
| 1 hGy | 10,000 rad |
| 10 hGy | 100,000 rad |
| 100 hGy | 1,000,000 rad |
Reverse conversion: Rad to Hectogray
1 rad × 0.0001 = 0.0001 hGy
1 rad = 0.0001 hectograys.
hectograys = rads × 0.0001
For a page dedicated to this direction, see Rad to Hectogray.
Understanding the Hectogray (hGy)
Hectogray is 100 gray units.
Understanding the Rad
Rad (rad) measures absorbed radiation dose. 'Radiation absorbed dose' — the US customary unit of absorbed radiation dose, fixed at exactly 0.01 gray. It is classified as a non-SI unit, still common in the US.
Where it's used: Still used in some US medical and historical contexts alongside the SI gray
Rad vs. gray. Both measure absorbed radiation dose; the gray is the modern SI unit while the rad is the older US customary unit, related by 1 gray = 100 rad exactly.
Uses of the Rad today
- US radiation therapy dose records (historically)
- US nuclear regulatory and medical physics contexts
Rad — sources
- NIST Guide to the SI, Appendix B — Lists the rad among non-SI units with an exact SI equivalence.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many rads are in 1 hectogray?
1 hectogray equals 10,000 rads, using the exact defined conversion factor rather than an estimate.
How do I convert hectogray to rad?
Multiply the hectogray value by 10000. The converter above does this instantly to whatever precision you set.
How do I convert rad back to hectogray?
Use the reverse factor: 1 rad equals 0.0001 hectograys. You can also use the swap control in the converter above to flip the direction instantly.
What is a hectogray?
Hectogray (hGy) is a unit of radiation.
What is a rad?
Rad (rad) measures absorbed radiation dose. 'Radiation absorbed dose' — the US customary unit of absorbed radiation dose, fixed at exactly 0.01 gray. It is classified as a non-SI unit, still common in the US.
Is the hectogray to rad conversion exact?
Yes. 'Radiation absorbed dose' — the US customary unit of absorbed radiation dose, fixed at exactly 0.01 gray. That fixed definition is what the converter above uses, so any rounding you see is a display choice, not a limitation of the math.
What is the difference between rad vs. gray?
Both measure absorbed radiation dose; the gray is the modern SI unit while the rad is the older US customary unit, related by 1 gray = 100 rad exactly.