Radiation dose conversion

1Millisievert = 1000Microsievert

1000

Ionizing Radiation

Sievert (Sv)0.001

Millisievert (mSv)1

Microsievert (μSv)1000

Rem (rem)0.1

Free online radiation dose conversion tool that supports two-way instant conversion of four commonly used radiation protection dose units: Sv, mSv, μSv, and rem. It is suitable for organizing dose equivalent and effective dose records, such as environmental monitoring, personal dosimeters, occupational exposure ledgers, and mSv and rem comparisons in medical imaging data. Note: This page does not convert absorbed dose Gy/rad, nor does it convert activity Bq/Ci or dose rate μSv/h. All calculations are done locally in the browser, and the data is not uploaded to the server.

Unit Converter

One-stop portal for 35+ unit conversions, suitable for continuing to process other physical quantities

Radioactivity Converter

When the original data is Bq or Ci, activity conversion should be used instead of dose conversion

About radiation dose, Sv/rem and the applicable boundaries of this page

This page deals with dose unit conversion in the context of radiation protection, that is, the conversion between Sv, mSv, μSv, and rem. These units usually appear in records of dose equivalent (equivalent dose) or effective dose (effective dose), and focus more on the protective significance of radiation on the human body or tissue, rather than just how much energy a substance absorbs.

Sv and rem belong to different unit systems of the same type of quantity. Sv is the mainstream writing method of the International System of Units, and rem is the old writing method used historically or in some areas. The two are in a fixed proportional relationship: 1 Sv = 100 rem. Since this relationship itself does not involve additional model assumptions, the conversion between these four units is a deterministic linear calculation, which is very suitable for report unification, historical document review, and cross-regional communication.

What needs to be strictly distinguished from it is the absorbed dose Gy/rad. Gy represents how many joules of energy are absorbed per kilogram of material, which is a quantity that is more physically deposited. Sv will further consider the radiation type and tissue weight, so it is closer to the context of radiation protection or biological effects. Precisely because there may be weighting factors involved, this page will not simplify the direct converter from Gy/rad to Sv/rem.

Another common source of confusion is activity versus dose rate. Bq and Ci talk about how many times a radioactive source decays per second, which is "how active the source is"; μSv/h and mSv/h are "the dose change rate per unit time"; and this page deals with a cumulative dose value itself. As long as the types of quantities are different, even if they both contain the word "radiation", they cannot be directly put into the same unit converter and calculated hard.

Therefore, the most suitable use of this page is to standardize the expression of the same dose value among the four writing methods of Sv, mSv, μSv, and rem. It is not responsible for determining health risks, medical diagnoses, occupational exposure compliance, or emergency response thresholds. In other words, it can help you unify the "ruler", but it will not explain for you what this value means in a specific scenario.

Use Cases

Quickly replace the rem unit in the old version of the US data with mSv or Sv to facilitate unification with the current SI standard
When μSv, mSv, and rem are mixed in personal dosimeters, environmental monitors, and radiation protection ledgers, unify them first and then file them
The cumulative dose needs to be unified into the same unit in occupational exposure records, annual summary tables, and training sign-in materials
When reading documents from international institutions, laboratories, and equipment manufacturers, align the Sv/rem writing method with the unit system used within the team
When collating training materials for hospital physicists, imaging departments, or patient education materials, unify the expressions of mSv and rem in texts from different sources
The nuclear industry, industrial flaw detection, accelerator laboratories and scientific research units should unify dose units when writing internal SOPs, training documents or drill materials
Convert the μικ magnitude readings in environmental radiation monitoring reports from μSv to mSv, or vice versa to a more intuitive μSv display
Compare the doses in the specifications of different brands of dosimeters, alarms and radiation detection equipment Units, confirm whether the display caliber is consistent
Rewrite the Sv, mSv, and rem that appear in news, popular science articles or emergency drill materials into units that are more familiar to the target audience
When sorting out college health physics, nuclear engineering, and radiation health coursework, replace the historical units in the questions with SI to make unified calculations
When preparing bilingual or multilingual documents in Chinese and English, retain both rem and mSv to reduce communication errors
When doing database cleaning, CSV standardization or BI reports, convert the multi-source dose fields into unified units before doing aggregate statistics
In radon exposure or environmental survey data, if the results are ultimately expressed in annual effective dose mSv, they can be unified into a single unit in the summary process
In safety training and desktop deductions, the dose values in different cases are unified into μSv or mSv to facilitate participants to quickly compare magnitudes
Replace the old unit of rem in NRC, EPA, or hospital radiation-safety training material with mSv or Sv to facilitate filing according to the current caliber.
When sorting out μSv, mSv, and rem readings in EPA RadNet notes, personal dosimeter logs, or lab monitoring records, unify the units first and then make statistics.
Synchronously display Sv / mSv / μSv / rem in hospital, university lab, or industrial safety reports to facilitate cross-department communication.

How to Use

Fill in the known dose value in the input box, supporting integers and decimals.
Select the source unit in the drop-down box on the left, optional Sv, mSv, μSv or rem.
Select the target unit in the drop-down box on the right, and the results will be updated immediately; if you need to view in reverse, click the swap button in the middle.
If you need to organize data, you can directly view the results of all units and copy the same dose value to documents or ledgers of different calibers at the same time.

Features

Real-time conversion of 4 radiation protection dose units: Sv, mSv, μSv, rem covering international SI writing and US/historical writing
Two-way real-time conversion: enter the value of any unit, and the results of the other units will be synchronized immediately, without clicking additional buttons
Clear linear proportional relationship: 1 Sv = 100 rem = 1000 mSv = 1000000 μSv, suitable for report review and cross-regional caliber unification
Clear tool boundaries: This page only deals with dose equivalents/effective dose units, and does not mix Gy, rad, Bq, Ci or μSv/h
Suitable for cross-regional data organization: rem is common in old European and American data, Sv/mSv/μSv is commonly used in Asian and international standards, this page can be quickly aligned
Supports decimal and smaller reading input, and can accurately convert from microsievert-level background volume to sievert-level cumulative volume
All unit results can be viewed at one time, suitable for writing the same dose value into training documents, ledgers and summary tables at the same time
Pure browser local calculation: no network requests, no server logs, dose records, occupational exposure data and internal documents will not be uploaded

What kind of radiation are you trying to convert?

Radiation-related terms can be easily confused. Confirm the type of quantity first before choosing the right tool and unit.

Type of amount	Representing unit	What is it describing	Does this page support	What to do
Dose equivalent / effective dose	Sv / mSv / μSv / rem	Cumulative dose or protective significance in the context of radiation protection	Supported	This is exactly what this page is about, it can be directly converted
Absorbed dose	Gy / mGy / rad	How much energy is absorbed by unit mass of material	Not supported	First confirm whether you are really dealing with absorbed dose, do not regard it directly as Sv/rem
activity	Bq / Ci	How many times does the radioactive source decay per second, reflecting the source strength	Not supported	Please use the radioactive activity conversion pageRadioactivity conversion
Dose rate	μSv/h / mSv/h	Dose change rate per unit time	Not supported	Needs to be combined with time integration or recording period first, this page does not do rate conversion

Best Practices

First distinguish between "total dose" and "dose rate"

80 μSv and 2.5 μSv/h both seem to have Sv, but the former is the cumulative amount and the latter is the unit time rate. Only the total dose value can be directly put into this page for conversion.

First confirm whether the amount in your hand is an effective dose/dose equivalent

If the original document says Gy, rad, Bq, or Ci, it is no longer the subject of this page. If you mix different amounts, the conclusion will be wrong.

Radioactivity conversion

When collating cross-regional data, keep the original units and give the SI system at the same time

Rem is still very common in the old North American data, while international standards are more biased towards Sv/mSv/μSv. When migrating reports, it is recommended that the text be unified in SI format and the original value of rem be retained in parentheses to facilitate review and traceability.

Record the organ, examination type, and exposure period together

It is also mSv, which may represent an examination, an annual accumulation, a certain organ dose equivalent, or it may be an environmental survey estimate. After the units are unified, contextual information must still be retained.

Do not simplify Gy/rad to Sv/rem and apply the ratio directly

Whether the values between Gy and Sv are close depends on the radiation type, tissue weight and usage context. When only doing unit organization, it is better to separate the concepts first than to directly replace them just to save trouble.

Unit conversion cannot replace medicine, occupational protection or emergency judgment

This page only helps you convert the same value into another way of writing. It will not tell you whether a certain dose value is "safe" or whether it requires disposal, nor can it replace the risk assessment process of a professional organization.

FAQ

What units does this radiation dose converter support?

This page currently supports 4 units: Sv, mSv, μSv, rem, which are all used for dose equivalent or effective dose records in the context of radiation protection. It should be noted that the current page does not support absorbed dose units such as Gy and rad, nor does it support activity units such as Bq and Ci, nor does it support μSv/h and mSv/h dose rates with time dimensions. First clarify what the amount is in your hand, and then convert it to avoid going astray.

1 Sv is equal to how many rem, mSv, μSv?

1 Sv = 100 rem = 1000 mSv = 1000000 μSv. In other words, 1 rem = 0.01 Sv = 10 mSv, 1 mSv = 1000 μSv. Since there is a fixed proportional relationship between these units, this page only does linear scaling and does not introduce additional assumptions. This is the most commonly used set of conversion relationships when collating radiation protection data from different countries and different eras.

What is the difference between Sv and rem?

They describe the same type of quantity, and the difference is mainly in the unit system. Sv (Sievert) belongs to the International System of Units and is the current mainstream standard writing; rem is a historical writing used earlier or in some areas. The relationship between the two is fixed at 1 Sv = 100 rem. Rem is often retained when seeing old US training materials, equipment manuals or historical ledgers.

What scenarios are mSv and μSv suitable for?

mSv is suitable for recording a more complete examination, an event, a stage or an annual cumulative dose; μSv is more suitable for describing smaller cumulative quantities or more precise readings. For example, μSv levels often appear in environmental background, short-term exposure, and single monitoring readings. They essentially differ only in the SI prefix: 1 mSv = 1000 μSv.

What is the difference between Gy/rad and Sv/rem?

Gy/rad represents absorbed dose, emphasizing how much energy is absorbed per unit mass of material; Sv/rem represents dose equivalent or effective dose, emphasizing the significance of protection after weighting the radiation type and human tissue. The former is more focused on physical deposition of energy, while the latter is more focused on radiation protection and biological effect characterization. Because radiation weight factors and tissue weight factors may be involved, this page will not directly convert Gy/rad to Sv/rem.

Why can't Bq/Ci and Sv/rem be interchanged?

Bq and Ci describe radioactive activity, that is, the amount of decay per unit time; Sv and rem describe the dose equivalent or effective dose, which is the protective significance of radiation on the human body or tissue. One is "how active the source is" and the other is "how much dose a person or object has received". The physical meaning is completely different, and the middle also depends on the nuclide, distance, shielding, time and exposure path. This page does not do such cross-concept conversions.

What is the difference between dose and dose rate? Can μSv/h be changed here?

Dose is a cumulative amount, such as 80 μSv, 0.3 mSv; dose rate is the rate of change per unit time, such as 2.5 μSv/h, 0.08 mSv/h. Although Sv is included in all units, the latter has the additional time dimension of "hourly". This page only changes the total dose itself and does not deal with the dose rate. If you have μSv/h, you should first confirm whether time integration is required before obtaining the cumulative dose.

Why do some reports only write "dose", but the unit is mSv?

In many radiation protection, environmental monitoring or medical materials, when the context has defaulted to "effective dose" or "dose equivalent", the report will directly write the unit as mSv or μSv, and the text will no longer repeat the complete term every time. When encountering this kind of writing, it is best to go back to the original report title, column names, footnotes or methods section to confirm whether it refers to effective dose, equivalent dose, or dose equivalent to a certain organ.

Can Gy be directly replaced by Sv on this page?

It cannot be replaced directly as a simple ratio. For some specific radiation types and specific discussion contexts, people will mention that Gy and Sv may be numerically close, but that depends on the radiation weighting factor, the irradiation geometric conditions, the tissue weighting factor and the usage scenario. In order to avoid misunderstanding the concept, this page only provides deterministic conversions between Sv, mSv, μSv, and rem.

Can this tool be used to determine health risks, make diagnoses, or recommend treatments?

No. This page is only responsible for unit conversion and does not explain the medical significance, occupational protection compliance, health risks or treatment options of a certain dose value. Under different circumstances, the same value may correspond to completely different types of exposure, organs, duration and exposure pathways. When it comes to diagnosis, interpretation of occupational exposure, or emergency decision-making, professional organizations and compliance processes must prevail.

Can this page be used offline? Will the data be uploaded?

Yes. After the page is loaded, all radiation dose conversions are performed locally in the browser, with no network requests, no server logs, and no form submissions. Your monitoring records, ledger data, training materials or internal report numbers will not be uploaded to the server, and will be cleared after closing the page.

Can I use this tool to collate mSv / rem data from NRC guidelines or personal dosimeters?

Yes, as long as the value you have is cumulative dose, dose equivalent or effective dose, and the unit is Sv, mSv, μSv or rem, you can convert it directly. If the original data is Bq, Ci, Gy, rad or μSv/h, it is not within the conversion range of this page.

Why do some older NRC, EPA, or hospital radiation-safety training materials still use rem instead of mSv?

Because many historical training materials, old equipment manuals and old ledgers continue to use the rem system, and current international and inter-agency communications more commonly use Sv / mSv / μSv. After unifying the old data to the SI caliber, it will be more reliable to conduct annual summary or cross-regional comparison.

Glossary

Sivert (Sv): A common SI dose unit used in radiation protection, used for dose equivalent or effective dose. 1 Sv = 100 rem.
Millisievert (mSv): 1 mSv = 0.001 Sv = 1000 μSv, commonly used to express effective doses at inspection, stage cumulative amounts or reporting levels.
Microsievert (μSv): 1 μSv = 0.000001 Sv = 0.001 mSv, suitable for expressing smaller cumulative amounts or finer readings.
Rem (rem): A dosage unit that was historically or still used in some areas and describes the same amount as Sv. 1 rem = 0.01 Sv = 10 mSv.
Dose equivalent (equivalent dose): The amount after introducing a radiation weight factor based on the absorbed dose, used to describe the difference in protection significance caused by different types of radiation.
Effective dose (effective dose): The amount based on the dose equivalent and then considering the tissue weight factor is more suitable for the context of overall protection and risk communication.
Absorbed dose: The energy absorbed by a unit mass of material, often expressed in Gy or rad. It is not the subject of direct conversion on this page.
Dose rate: The rate of dose change per unit time, commonly written in μSv/h, mSv/h. Because of the extra time dimension, it cannot be directly used as the total dose.
Activity: The number of decays of a radioactive source per unit time, commonly expressed as Bq or Ci. It reflects the source strength, not the dose received by the human body.

Sv / rem conversion cheat sheet

These fixed ratios are most commonly used for old data migration and caliber unification.

Basic unit	Equivalent expression	Common context
1 Sv	100 rem = 1000 mSv = 1000000 μSv	High-level cumulative dose, upper standard caliber
1 rem	0.01 Sv = 10 mSv = 10000 μSv	North American historical materials, old training materials
1 mSv	0.001 Sv = 0.1 rem = 1000 μSv	Inspection, stage cumulative amount, common report level expression
1 μSv	0.000001 Sv = 0.001 mSv = 0.0001 rem	Smaller cumulative amounts or fine monitoring readings

Don’t confuse the writing methods of common radiation records

Example writing methods	What is it	Can this page be converted directly	Remarks
0.25 mSv	Cumulative dose/effective dose	Yes	Typical total dose writing method can be directly replaced by μSv, Sv or rem
85 μSv	Smaller cumulative amount	Yes	Suitable for direct replacement by mSv or rem for document unification
2.5 μSv/h	Dose rate	No	With time dimension, you need to combine the duration first to get the cumulative dose
30 Bq/m³	Activity concentration	No	It is not a dose unit and cannot be placed directly in Sv/rem In the converter
5 Gy	absorbed dose	not	belongs to absorbed dose and cannot be directly rewritten linearly as Sv/rem

Privacy & Security

All radiation dose conversions on this page are completed in your browser. The monitoring records, ledger data, training materials and internal report numbers you enter will not leave your device - there are no network requests, no server logs, and the input will be cleared after closing the page. For occupational exposure data, environmental monitoring data and medical-related documents, this page will not collect or store any content.

Authoritative References

HHS REMMREMM Radiation Measurements
ICRPaediaICRPaedia - Effective Dose