Radiation Converter
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| Unit | Equivalent Value |
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Radiation absorbed dose rate measures the speed at which ionizing radiation energy is deposited per unit mass of matter or human tissue over time. In radiation oncology, nuclear physics, and radiation protection, dose rates link total absorbed energy with biological impact. The International System of Units (SI) measures absorbed dose rate in Gray per second (Gy/s) or Watts per kilogram (W/kg), whereas traditional health physics uses rad per second (rad/s), and biological dose equivalent rate is measured in Sievert per second (Sv/s) or rem per second (rem/s).
Our free online Radiation Converter provides instant, high-precision conversions across all SI, traditional CGS, medical oncology, and radiological protection dose rate units:
- Gray per Second to Rad per Second: Multiply Gy/s by
100(1 Gy/s = 100 rad/s = 100 cGy/s). - Rad per Second to Gray per Second: Multiply rad/s by
0.01(1 rad/s = 0.01 Gy/s = 1 cGy/s). - Gray per Second to Watts per Kilogram:
1 Gy/s = 1 W/kg = 1 J/(kg·s)(exact 1:1 energy rate equivalence). - Sievert per Second to Rem per Second (Gamma/Beta Q = 1): Multiply Sv/s by
100(1 Sv/s = 100 rem/s). - Gray per Second to Milligray per Second: Multiply Gy/s by
1,000(1 Gy/s = 1,000 mGy/s).
Master Radiation Absorbed Dose Rate Unit Conversion Table
The table below displays exact relationships, SI power multipliers, and traditional health physics equivalents relative to 1 Gray per second (Gy/s):
| Radiation Dose Rate Unit | Symbol | Exact Value in Gray / Sec (Gy/s) | Equivalent in Rad / Sec (rad/s) | System & Application Field |
|---|---|---|---|---|
| 1 Gray per second | Gy/s |
1.0 Gy/s |
100.0 rad/s |
SI Base Absorbed Dose Rate |
| 1 Centigray per second | cGy/s |
0.01 Gy/s (10-2 Gy/s) | 1.0 rad/s |
Radiation Oncology Clinical Standard |
| 1 Milligray per second | mGy/s |
0.001 Gy/s (10-3 Gy/s) | 0.1 rad/s | Diagnostic Radiology Imaging Rate |
| 1 Microgray per second | μGy/s |
0.000001 Gy/s (10-6 Gy/s) | 0.0001 rad/s | Environmental Protection Monitoring |
| 1 Nanogray per second | nGy/s |
1.0 × 10-9 Gy/s | 1.0 × 10-7 rad/s | Terrestrial Background Radiation Rate |
| 1 Watt per kilogram | W/kg |
1.0 Gy/s |
100.0 rad/s | SI Specific Power Absorption Rate |
| 1 Joule / kilogram / second | J/(kg·s) |
1.0 Gy/s |
100.0 rad/s | SI Physical Mass Energy Rate |
| 1 Rad per second | rad/s, rd/s |
0.01 Gy/s (1 cGy/s) | 1.0 rad/s |
Traditional CGS Absorbed Dose Rate |
| 1 Sievert per second (Q=1) | Sv/s |
1.0 Gy/s |
100.0 rad/s (100 rem/s) | SI Biological Equivalent Dose Rate |
| 1 Rem per second (Q=1) | rem/s |
0.01 Gy/s (1 cGy/s) | 1.0 rad/s |
Traditional Biological Dose Rate |
Step-by-Step Calculation Example
To convert a linear accelerator (LINAC) oncology dose delivery rate of 6.0 Gray / minute into Centigray per second (cGy/s) and rad per second (rad/s):
6.0 Gy / minute ÷ 60 seconds = 0.10 Gray / second (0.10 Gy/s)
0.10 Gy/s × 100 = 10.0 cGy/s = 10.0 rad/s
Thus, a 6.0 Gy/min LINAC treatment beam delivers radiation at a rate of 10.0 cGy/s (10 rad/s).
Medical Oncology & Radiological Protection Benchmark Rates
Below is a comparative reference chart showing dose delivery rates across medical cancer therapy, environmental radiation, and nuclear reactor environments:
| Radiation Environment / Procedure | Dose Rate in Gray / Sec (Gy/s) | Equivalent in Rad / Sec (rad/s) | Clinical & Health Context |
|---|---|---|---|
| Natural Background Radiation | ~7.5 × 10-11 Gy/s | ~7.5 × 10-9 rad/s | Normal sea-level exposure (~2.4 mSv/year) |
| Conventional Radiotherapy (LINAC) | 0.033 to 0.10 Gy/s | 3.33 to 10.0 rad/s (cGy/s) | Standard EBRT cancer treatment beam (2 to 6 Gy/min) |
| Lethal Acute Exposure Threshold (LD50) | 0.10 Gy/s for 45 seconds | 10.0 rad/s (4.5 Gy total) | 50% mortality threshold without medical intervention |
| FLASH Radiotherapy (Experimental) | > 40.0 Gy/s | > 4,000 rad/s | Ultra-high dose rate delivery in milliseconds to spare healthy tissue |
| Nuclear Reactor Inner Pressure Vessel | > 100.0 Gy/s | > 10,000 rad/s | High-intensity neutron and gamma flux within core |
History & Standards: Louis Harold Gray vs. Rolf Sievert vs. CGS Rad
Louis Harold Gray and the SI Gray (1975)
The SI unit of absorbed dose is named in honor of British physicist and radiobiology pioneer Louis Harold Gray (1905–1965), who defined the relationship between radiation energy absorption and cell survival. In 1975, the 15th General Conference on Weights and Measures (CGPM) adopted the Gray (Gy), defined as 1 Joule of energy absorbed per kilogram of mass (1 Gy = 1 J/kg), replacing the older CGS rad unit.
Rolf Sievert and Equivalent Biological Dose (1979)
Because different types of radiation (alpha, beta, gamma, neutrons) cause varying amounts of biological harm at identical absorbed doses, Swedish medical physicist Rolf Sievert (1896–1966) developed biological equivalent weighting. In 1979, the CGPM adopted the Sievert (Sv) to measure biological dose equivalent (Sv = Gy × Q, where Q = 1 for gamma/X-rays). The Sievert replaced the legacy rem (Roentgen equivalent man; 1 Sv = 100 rem).
The CGS Rad (1953)
Created in 1953 by the International Commission on Radiation Units and Measurements (ICRU), the rad (acronym for Radiation Absorbed Dose) was defined as 100 ergs of energy absorbed per gram of material (0.01 J/kg). Consequently, 1 Gray = 100 rads, and 1 Gy/s = 100 rad/s = 100 cGy/s.
For thermodynamic and kinetic energy calculations, visit our Energy Calculator or check power rates on our Power Calculator. For general scientific unit transformations, explore our Conversion Calculator.
Frequently Asked Questions (FAQ)
How many rad/s are in 1 Gray per second (Gy/s)?
There are exactly 100 rad per second (100 rad/s) in 1 Gray per second (Gy/s).
What is the relationship between centigray/second (cGy/s) and rad/second (rad/s)?
They are identical: 1 centigray per second (cGy/s) = 1 rad per second (rad/s).
Why is 1 Gy/s equal to 1 Watt per kilogram (W/kg)?
Because 1 Gray is defined as 1 Joule per kilogram (1 J/kg). Since 1 Watt is 1 Joule per second (1 W = 1 J/s), absorbing 1 Gy/s means transferring 1 Watt of power into 1 kilogram of mass (1 Gy/s = 1 W/kg).
What is FLASH radiotherapy in medical physics?
FLASH radiotherapy is an advanced cancer treatment technique that delivers ultra-high radiation dose rates exceeding 40 Gray per second (40 Gy/s) in millisecond pulses, effectively destroying tumors while sparing surrounding healthy tissue.