Sievert is equivalent dose.
Sieverts to Rems Converter — Sv to rem
Convert Sievert (Sv) to Rem (rem) using the exact conversion factor (1 sievert = 100 rem). See the formula, worked examples, conversion table, unit comparison, history, and common uses.
Sieverts to Rems 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.
Rem is 0.01 sievert.
Result = input x 1 / 0.01.
Equivalent Dose units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Sieverts to Rems
Sievert and Rem 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. Sievert is typically associated with universal — SI derived unit used worldwide in radiation protection, while Rem is typically associated with still widely used in the United States alongside the SI sievert.
Formula
rems = sieverts × 100
This factor comes from each unit's defined relationship to the category's base unit: 1 sievert equals 1 base unit, and 1 rem equals 0.01 base units, so dividing one by the other gives the direct sievert-to-rem factor of 100.
Simple example
1 Sv × 100 = 100 rem
1 sievert = 100 rems.
Real-world example
10 Sv × 100 = 1,000 rem
10 sieverts = 1,000 rems.
Conversion table
| Sievert (Sv) | Rem (rem) |
|---|---|
| 0.001 Sv | 0.1 rem |
| 0.01 Sv | 1 rem |
| 0.1 Sv | 10 rem |
| 1 Sv | 100 rem |
| 10 Sv | 1,000 rem |
| 100 Sv | 10,000 rem |
Reverse conversion: Rem to Sievert
100 rem × 0.01 = 1 Sv
100 rems = 1 sievert.
sieverts = rems × 0.01
For a page dedicated to this direction, see Rem to Sievert.
Sievert vs. Rem
| Aspect | Sievert | Rem |
|---|---|---|
| Family | SI derived unit | non-SI unit, still common in the US |
| Typical use | Radiation safety dose limits for workers and the public | US occupational radiation dose limits and monitoring |
| Where it's used | Universal — SI derived unit used worldwide in radiation protection | Still widely used in the United States alongside the SI sievert |
Understanding the Sievert
Sievert (Sv) measures equivalent radiation dose. The SI derived unit of equivalent radiation dose, weighting the physically absorbed dose (in gray) for how biologically damaging the specific type of radiation is. It is classified as a SI derived unit.
Where it's used: Universal — SI derived unit used worldwide in radiation protection
Sievert vs. gray. The gray measures physically absorbed radiation energy; the sievert adjusts that figure for biological harm, since equal absorbed doses of different radiation types (e.g. alpha particles vs. X-rays) can cause very different amounts of damage.
Uses of the Sievert today
- Radiation safety dose limits for workers and the public
- Medical imaging (CT scan, X-ray) dose reporting
- Background and environmental radiation exposure reporting
History of the Sievert
The sievert is named after Rolf Sievert (1896–1966), a Swedish medical physicist whose research on radiation measurement and safety standards was foundational to modern radiation protection practice; the unit was adopted by the CGPM in 1977.
Historical origin. Sievert was not the invention of a single named person; it developed through the process described above.
Understanding the Rem
Rem (rem) measures equivalent radiation dose. 'Roentgen equivalent man' — the US customary unit of equivalent radiation dose, fixed at exactly 0.01 sievert. It is classified as a non-SI unit, still common in the US.
Where it's used: Still widely used in the United States alongside the SI sievert
Rem vs. sievert. Both measure equivalent radiation dose; the sievert is the modern SI unit while the rem is the older US customary unit, related by 1 sievert = 100 rem exactly.
Uses of the Rem today
- US occupational radiation dose limits and monitoring
- US nuclear regulatory reporting
- US medical radiation dose records
Sievert — sources
- BIPM SI Brochure, 9th edition — Official definition of the sievert as an SI derived unit.
Rem — sources
- US NRC (Nuclear Regulatory Commission) — glossary — Definition and continued regulatory use of the rem in the United States.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many rems are in 1 sievert?
1 sievert equals 100 rems, using the exact defined conversion factor rather than an estimate.
How do I convert sievert to rem?
Multiply the sievert value by 100. The converter above does this instantly to whatever precision you set.
How do I convert rem back to sievert?
Use the reverse factor: 1 rem equals 0.01 sieverts. You can also use the swap control in the converter above to flip the direction instantly.
What is a sievert?
Sievert (Sv) measures equivalent radiation dose. The SI derived unit of equivalent radiation dose, weighting the physically absorbed dose (in gray) for how biologically damaging the specific type of radiation is. It is classified as a SI derived unit.
What is a rem?
Rem (rem) measures equivalent radiation dose. 'Roentgen equivalent man' — the US customary unit of equivalent radiation dose, fixed at exactly 0.01 sievert. It is classified as a non-SI unit, still common in the US.
Is the sievert to rem conversion exact?
Yes. 'Roentgen equivalent man' — the US customary unit of equivalent radiation dose, fixed at exactly 0.01 sievert. 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 sievert vs. gray?
The gray measures physically absorbed radiation energy; the sievert adjusts that figure for biological harm, since equal absorbed doses of different radiation types (e.g. alpha particles vs. X-rays) can cause very different amounts of damage.
Where is the sievert still used today?
Universal — SI derived unit used worldwide in radiation protection