Convert Rems/Second to Exagrays/Second
Rem/Second (rem/s) to Exagray/Second (EGy/s) radiation dose rate conversion — enter any value below to get an instant result, or use the table for common values.
Results from this calculator are estimates provided for general informational purposes only, based on formulas, rates, and standards commonly accepted as of 2026. Figures may differ slightly from other calculators or professional sources due to rounding methods, differing assumptions, or regional regulations, and rules may change over time. Always consult a qualified professional — such as a financial advisor, healthcare provider, or other relevant specialist — before making decisions based on these results.
Result
1 rem/s = 1E-20 EGy/s
1 Rem/Second = 1E-20 Exagrays/Second
1 Exagray/Second = 1E+20 Rems/Second
1 rem/s in every supported unit
Conversion chart: Rem/Second to Exagrays/Second
Conversion table
| Rem/Second (rem/s) | Exagray/Second (EGy/s) |
|---|---|
| 0.01 rem/s | 1E-22 EGy/s |
| 0.1 rem/s | 1E-21 EGy/s |
| 1 rem/s | 1E-20 EGy/s |
| 2 rem/s | 2E-20 EGy/s |
| 3 rem/s | 3E-20 EGy/s |
| 5 rem/s | 5E-20 EGy/s |
| 10 rem/s | 1E-19 EGy/s |
| 20 rem/s | 2E-19 EGy/s |
| 50 rem/s | 5E-19 EGy/s |
| 100 rem/s | 1E-18 EGy/s |
| 1000 rem/s | 1E-17 EGy/s |
Rem/Second (rem/s)
Definition: The older CGS-derived dose-equivalent-rate unit, equal to 0.01 sievert per second — one rem ("roentgen equivalent man") delivered every second.
History: The rem was the standard US unit for biologically-weighted dose rate for decades before the sievert became the international SI standard, paralleling how the rad preceded the gray for absorbed dose.
Current use: Still appears in US occupational radiation-safety regulations and older personnel dosimetry records, listed here at the same numeric value as rad/second since both apply the same weighting-factor-of-1 assumption for common radiation types.
Exagray/Second (EGy/s)
Definition: An SI-prefixed multiple of the gray-per-second equal to 10^18 gray of absorbed dose delivered every second — a rate so extreme it has no real-world instrument reading, existing only as a theoretical ceiling in dose-rate scale comparisons.
History: It exists automatically as a consequence of the SI's decimal-prefix system, which applies exa- uniformly across every coherent derived unit rather than being independently defined for radiation dose rate.
Current use: Used only in theoretical physics discussions of extreme radiation environments, such as the instantaneous dose rates modeled near a nuclear detonation's fireball or in certain astrophysical radiation-burst scenarios.
Supported Units
| Unit | Symbol | In Gy/s |
|---|---|---|
| Exagray/Second | EGy/s | 1E+18 Gy/s |
| Petagray/Second | PGy/s | 1E+15 Gy/s |
| Teragray/Second | TGy/s | 1E+12 Gy/s |
| Gigagray/Second | GGy/s | 1E+09 Gy/s |
| Megagray/Second | MGy/s | 1000000 Gy/s |
| Kilogray/Second | kGy/s | 1000 Gy/s |
| Hectogray/Second | hGy/s | 100 Gy/s |
| Dekagray/Second | daGy/s | 10 Gy/s |
| Gray/Second | Gy/s | 1 Gy/s |
| Decigray/Second | dGy/s | 0.1 Gy/s |
| Centigray/Second | cGy/s | 0.01 Gy/s |
| Milligray/Second | mGy/s | 0.001 Gy/s |
| Microgray/Second | µGy/s | 1E-06 Gy/s |
| Nanogray/Second | nGy/s | 1E-09 Gy/s |
| Picogray/Second | pGy/s | 1E-12 Gy/s |
| Femtogray/Second | fGy/s | 1E-15 Gy/s |
| Attogray/Second | aGy/s | 1E-18 Gy/s |
| Rad/Second | rd/s | 0.01 Gy/s |
| Joule/Kilogram/Second | J/(kg·s) | 1 Gy/s |
| Watt/Kilogram | W/kg | 1 Gy/s |
| Sievert/Second | Sv/s | 1 Gy/s |
| Rem/Second | rem/s | 0.01 Gy/s |
About These Parameters
- Value
- The dose rate reading you want to convert, expressed in the "From" unit. Accepts decimals, and can represent anything from a faint background reading in nanogray/second to a therapeutic radiotherapy beam's centigray/second delivery rate.
- From Unit
- The unit your dose-rate reading is currently measured in — a dosimeter's microgray/second display, an older instrument's rad/second scale, or a radiotherapy machine's centigray/second output.
- To Unit
- The unit you want the result converted into. Use the swap button to flip From and To instantly, which is handy when translating an older rad/second or rem/second reading into the modern SI gray/second or sievert/second.
How Radiation Conversion Works
The Formula
Every unit here is defined by a fixed multiplier relative to gray per second. To convert a value from one unit to another:
result = value × (factor of "From" unit ÷ factor of "To" unit)
For Rem/Second → Exagray/Second: multiply by 1E-20. For example, 1 rem/s × 1E-20 = 1E-20 EGy/s.
Dose Rate vs. Dose, Activity, and Exposure
A radiation monitor's alarm threshold is set in dose rate, not total dose, because rate is what determines whether it's safe to keep standing where you are right now. A source's activity in becquerel or curie tells you how radioactive the material is, but says nothing about the dose rate someone actually receives from it — that depends on distance, shielding, and the type of radiation emitted. Exposure in roentgen or coulomb/kilogram measures ionization specifically in air from X-rays and gamma rays, a narrower and historically older quantity than the general absorbed-dose-rate concept gray/second represents. Keeping these four quantities straight is essential in radiation safety work, since mixing up a source's activity with the dose rate it delivers at a given distance is a genuinely dangerous error.
Why Gray/Second and Watt/Kilogram Are the Same Thing
A watt is defined as one joule per second, so dividing a power reading in watts by the mass being irradiated, in kilograms, gives exactly the same number as a gray/second dose rate — both are "energy per time per mass," just framed differently. Engineers doing radiation-shielding or material-heating calculations often think in terms of power flux into a material (watts per kilogram), while dosimetrists and health physicists think in terms of a live dose-rate reading (gray per second); the two communities are describing the identical physical quantity through different professional habits.
Example
A dose rate of 1 rem/s equals 1E-20 EGy/s. For scale, natural background radiation delivers roughly 100-300 nanogray per second at ground level, a typical diagnostic X-ray delivers on the order of a few milligray/second during the brief exposure, and a therapeutic radiotherapy beam commonly runs at several centigray per second while actively treating a tumor.
Frequently Asked Questions
How many Exagrays/Second are in 1 Rem/Second?
1 Rem/Second (rem/s) equals exactly 1E-20 Exagrays/Second (EGy/s).
What's the difference between gray/second and gray?
Gray/second is a rate — how much dose is being delivered right now, per second. Gray alone (covered by the separate Radiation-Absorbed-Dose Converter) is a cumulative total with no time component. Multiplying a gray/second dose rate by the number of seconds of exposure gives you the total absorbed dose in gray.
Why are sievert/second and gray/second numerically equal here?
Sievert applies a biological weighting factor to the raw absorbed-energy rate that gray measures, to account for how damaging different radiation types are to tissue. For X-rays, gamma rays, and beta radiation that weighting factor equals exactly 1, so the two units read the same number for those common radiation types — but they remain conceptually different quantities (physical dose vs. biologically weighted dose), which is why sievert is used for radiation-protection limits rather than gray.
Is rad/second the same thing as gray/second?
No — one rad/second equals 0.01 gray/second, since the rad is the older, smaller CGS-derived unit that the gray replaced in 1975. A dose rate of 1 gray/second is the same as 100 rad/second.
Does dose rate tell me how radioactive a source is?
No — that's activity (becquerel or curie), measured by the separate Radiation-Activity Converter. Dose rate tells you how much energy is being absorbed per second by something near the source, which depends on the source's activity but also on distance, shielding, and radiation type. A highly active source far away or well-shielded can deliver a low dose rate, while a much less active source held close can deliver a higher one.