Radiation Dose Rate Converter
Convert absorbed dose rate of ionising radiation between grays per second, rads per second and other related SI units.
Written by Rahman · Last reviewed
Quick answer
This converts absorbed dose rate: how fast radiation energy is deposited in matter. The SI unit is the gray per second, which is one joule per kilogram per second. One rad per second is 0.01 Gy/s. Dose rate multiplied by exposure time gives the total absorbed dose.
| Gray per second (Gy/s) | 1 |
| Milligray per second (mGy/s) | 1000 |
| Microgray per second (µGy/s) | 1000000 |
| Rad per second (rad/s) | 100 |
| Joule per kilogram per second (J/(kg·s)) | 1 |
About the Radiation Dose Rate Converter
This converter handles the absorbed dose rate of ionising radiation: how quickly radiation energy is delivered to matter. The SI unit is the gray per second.
It is used in radiation safety, medical physics and nuclear work.
Three different questions, three different units
Radiation measurements are reported in units that are routinely treated as interchangeable and are not. Each answers a separate question, and a figure quoted without its unit carries almost no information.
The becquerel measures activity: how many nuclear decays a source produces per second. It describes the source and says nothing about what any object receives. The gray measures absorbed dose: energy deposited per kilogram of material. The sievert measures equivalent dose, which weights the absorbed dose by how damaging that type of radiation is to biological tissue.
- Activity is a property of the material. Absorbed dose is a property of what was exposed. They are not convertible without knowing the geometry, distance and shielding involved.
- A gray and a sievert are both joules per kilogram dimensionally, but the sievert carries a weighting factor that depends on the radiation type, so they are equal only for some kinds of radiation and not others.
- This page handles absorbed dose rate specifically, in gray per second. Activity and exposure have their own converters on this site.
Rate and total, and the older units
A dose rate is not a dose. Gray per second describes how quickly energy is being deposited; multiplying by the exposure time gives the total absorbed dose in gray. The same total can arrive as a high rate briefly or a low rate over a long period, and the two are not equivalent in their effects.
Older units are still encountered in literature and on legacy instruments. The rad is the CGS predecessor of the gray, at exactly one hundredth of it, so 1 Gy is 100 rad. The rem stands in the same relationship to the sievert, and the curie to the becquerel.
- Reading a rate as a total, or the reverse, is an error of whatever the exposure duration happens to be.
- Sub-multiples dominate in practice (milligray and microgray per second) because the base unit is large relative to most measurements.
- Dose limits, safety thresholds and any interpretation of what a measurement means for health are matters for a qualified radiation protection professional. This converter changes units and nothing else.
Frequently Asked Questions
What does this radiation converter measure?
⌄
It converts absorbed dose rate: the rate at which radiation energy is delivered, in gray per second.
What is a gray?
⌄
A gray is the SI unit of absorbed radiation dose, equal to one joule of energy absorbed per kilogram of matter.
Where is dose rate used?
⌄
It is used in radiation protection, radiotherapy planning and monitoring around nuclear facilities.