Our conversion tool allows you to convert radiation units quickly and accurately from one system to another. This way of converting units is a solution for everyone who works with radiation units that we express in different units of measurement.

What is Radiation

Radioactivity is a natural property of certain substances. There are natural and artificial sources of radiation.

Radioactive substances have an unstable atomic nucleus that decays spontaneously. In doing so, high-energy radiation, colloquially known as radioactive radiation, is emitted. People cannot feel this radiation with their senses.

The three main types of radiation are alpha, beta, and gamma radiation. Alpha and Beta radiation arise by the spontaneous transformation of an unstable atomic nucleus into another nucleus. Gamma radiation occurs when the atomic nucleus emits excess energy.

Absorbed dose units

When ionizing radiation hits biological tissue, the tissue absorbs it. The absorbed energy with the mass of biological tissue is called the absorbed dose. We express it in gray units (Gy). With the help of a radiation converter, you can convert absorbed radiation doses into the following units of measurement:
– milligray (mGy),
– microgray (µGy),
– centigray (cGy), and
– rad (rad).

The biological radiation effect depends on the type of radiation and the absorbed energy. So, we multiply the absorbed dose for each type of radiation by the weight factor.

Equivalent dose units

An equivalent dose of physical size records the biological effect of radioactive radiation. Dose equivalent characterizes the absorbed dose that the body absorbs, taking into account the biological effects.

Radiation exposure can leave consequences externally or internally. Through the introduced radioactive substances, organs and tissues are exposed to different loads because their sensitivity to radiation is different. For this reason, scientists have established a weighting factor to calculate the actual radiation risk to organs and tissues. You can use them to calculate the effective dose equivalent for an organ or specific tissue.

Thus you obtain an equivalent dose as a measure of biological efficiency. Your unit is “Sievert.” It is named after the Swedish radiation researcher Rolf Sievert (1898 – 1966).

1 sievert (Sv) corresponds to 1 joule per kilogram.

Because human organs and tissues are differently sensitive, we also consider the weight factor. It results in equivalent doses for individual organs/tissues (organ dose). It is also reported in sievert. In addition to Sievert, you can convert the amount into the following units using a converter:
– millisievert (mSv),
– millirems (mrem),
– microsievert (μSv),
– rem – roentgen equivalent man (rem),
– banana equivalent dose (BED).

Effective dose units

The sum of all the doses of organs and tissues is the effective dose. You express it in sievert.

If ionizing radiation hits biological tissue (such as in the human body), it interacts and can cause so-called stochastic radiation effects (such as cancer). The likelihood of such radiation effects depends on the effective dose level.

Human organs or tissues are differently sensitive to these effects. For example, human skin is less sensitive to ionizing radiation than various internal organs.

OrgansTissue weight factors
Redbone marrow0.13
Bone surface0.01
Salivary glands0.01
The rest of the body0.12
In total1.00
Tissue weight factors in human organs

The effective dose takes this into account and is used to assess the risk of stochastic effects of radiation.

The effective dose is obtained first by multiplying the equivalent doses of organs determined by the appropriate tissue weight factor. Tissue weight factors indicate tissue sensitivity to the effects of stochastic radiation. You can add equivalent doses of organs to get an effective dose.

The unit of effective dose is Sievert (Sv). One sievert corresponds to 1 joule per kilogram (J/kg). For example, millisievert (mSv) or microsievert (µSv) are commonly used in radiation protection practice.

Effects of Radiation on the Body

Biological action is the effect of radiation on the human body and other living beings. In particular, it can lead to immediate damage (acute radiation damage). Cause damage that becomes visible only after years (late damage). They cause genetic damage (hereditary damage) that occurs only in offspring. One of the genetic diseases is cholesterol. You can calculate the cholesterol ratio on our calculator.

All these changes and clinical pictures resulting from exposure to radioactive radiation are summarized under the term radiation sickness. The cells are damaged mainly by radioactive radiation. The biological effects on organisms depend, among other things, on how much radiation the body absorbs.

International System of Units (SI) Unit and Common Unit

The International System of Units, abbreviated SI (from French: Système International d’Unités), is based on the International System of Quantities (ISQ). This metric system of units, introduced in 1960, is the most widespread system of units for physical quantities worldwide today.

 SI Units*Common Units
Radioactivitybecquerel (Bq)curie (Ci)
Absorbed Dosegray (Gy)rad
Dose Equivalentsievert (Sv)rem
Exposurecoulomb/kilogram (C/kg)roentgen (R)
SI units vs. Common units

The following table provides an overview of the different dose dates.

ActivityRadioactive decay over timePhysical sizeBecquerel = 1/s
Absorbed doseAbsorbed energy by massPhysical sizeGray = J/kg
Equivalent doseWeighted absorbed dose, depending on the biological efficiency of different types of radiationBiologically derived quantitySievert = J/kg
Equivalent organ doseAbsorbed dose multiplied by a radiation weighting factor, based on organsBiologically derived quantitySievert
Effective doseThe sum of all equivalent doses multiplied by the tissue weight factorBiologically derived quantitySievert
Different doses and units

Conversion Equivalence Table

In the next table, you can find conversions between different units for radiation:

0.001 rem=1 mrem=0.01 mSv
0.01 rem=10 mrem=0.1 mSv
0.1 rem=100 mrem=1 mSv=0.001 Sv
I rem=1,000 mrem=10 mSv=0.01 Sv
10 rem==100 mSv=0.1 Sv
100 rem==1,000 mSv=1 Sv
1,000 rem==10 Sv
Conversion Equivalence Table

How to use a radiation converter to change between radiation units?

Here are a few steps that will help you to use a radiation converter to change between radiation units:

1. Select the radiation unit you want to convert.
2. Enter the value of the radiation unit you selected. If you are going to convert the absorbed dose, enter the value in the upper part of the converter. For equivalent/effective, enter the value in the lower part.
3. The calculator will automatically convert the entered value into different units of measure from the drop-down list.

For example, if you enter that the equivalent/effective dose is 0.001 rem, the converter will convert the value to 1 mrem and 0.01 mSv.


1. What is radiation converted?

You can use a radiation converter to convert radiation units – absorbed doses, equivalent or effective doses. Depending on the radiation dose, you will use different units of measurement. Popular units for expressing the absorbed dose are mGy and rads. For the conversion of the equivalent dose, you can use mSv, rems or BEDs – banana equivalent dose.

2. How many mrem per year is safe?

According to the National Radiation Protection and Measurement Council (NCRP), the average annual radiation dose per year is 620 mrem.

3. How much radiation can a human take?

If the dose is 100 mSv, it will cause a lower damage threshold for the unborn child. In the case of acute exposure of 1000 mSv, acute effects of radiation occur above this limit (headache, nausea, vomiting). Without medical intervention, 50 percent of exposed people will die after 3-6 weeks if the dose is between 3000 and 4000 mSv.

4. How many REM is 1000 mrem?

According to the Conversion Equivalence Table, 1000 mrem is 1 rem.