Rem is 0.01 sievert.
Rems to Sieverts Converter — rem to Sv
Convert Rem (rem) to Sievert (Sv) using the exact conversion factor (1 rem = 0.01 sievert). See the formula, worked examples, conversion table, unit comparison, history, and common uses.
Rems to Sieverts 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.
Sievert is equivalent dose.
Result = input x 0.01 / 1.
Equivalent Dose units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Rems to Sieverts
Rem and Sievert 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. Rem is typically associated with still widely used in the United States alongside the SI sievert, while Sievert is typically associated with universal — SI derived unit used worldwide in radiation protection.
Formula
sieverts = rems × 0.01
This factor comes from each unit's defined relationship to the category's base unit: 1 rem equals 0.01 base units, and 1 sievert equals 1 base unit, so dividing one by the other gives the direct rem-to-sievert factor of 0.01.
Simple example
1 rem × 0.01 = 0.01 Sv
1 rem = 0.01 sieverts.
Real-world example
10 rem × 0.01 = 0.1 Sv
10 rems = 0.1 sieverts.
Conversion table
| Rem (rem) | Sievert (Sv) |
|---|---|
| 0.001 rem | 0.00001 Sv |
| 0.01 rem | 0.0001 Sv |
| 0.1 rem | 0.001 Sv |
| 1 rem | 0.01 Sv |
| 10 rem | 0.1 Sv |
| 100 rem | 1 Sv |
Reverse conversion: Sievert to Rem
0.01 Sv × 100 = 1 rem
0.01 sieverts = 1 rem.
rems = sieverts × 100
For a page dedicated to this direction, see Sievert to Rem.
Rem vs. Sievert
| Aspect | Rem | Sievert |
|---|---|---|
| Family | non-SI unit, still common in the US | SI derived unit |
| Typical use | US occupational radiation dose limits and monitoring | Radiation safety dose limits for workers and the public |
| Where it's used | Still widely used in the United States alongside the SI sievert | Universal — SI derived unit used worldwide in radiation protection |
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
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.
Rem — sources
- US NRC (Nuclear Regulatory Commission) — glossary — Definition and continued regulatory use of the rem in the United States.
Sievert — sources
- BIPM SI Brochure, 9th edition — Official definition of the sievert as an SI derived unit.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many sieverts are in 1 rem?
1 rem equals 0.01 sieverts, using the exact defined conversion factor rather than an estimate.
How do I convert rem to sievert?
Multiply the rem value by 0.01. The converter above does this instantly to whatever precision you set.
How do I convert sievert back to rem?
Use the reverse factor: 1 sievert equals 100 rems. You can also use the swap control in the converter above to flip the direction instantly.
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.
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.
Is the rem to sievert 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 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.
Where is the rem still used today?
Still widely used in the United States alongside the SI sievert