Radiation dose converter
Convert between sieverts, rem and gray, and compare the dose with a dental x-ray, a long flight and a year of natural background.
That's 10× as much as a chest x-ray, while a year of background is 2.4× higher. That is about 0.4167× a year of natural background radiation.
What it means
How much is that?
Information only. Gray measures energy absorbed; sievert weights it for biological harm, and for x-rays the two are numerically equal.
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Your dose in every unit
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Three things worth knowing
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1 Sv = 100 rem
Move two decimal places: 1 mSv is 100 mrem. Most medical doses land in the millisievert range.
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A banana of radiation
Bananas contain potassium-40, giving about 0.1 µSv each. The "banana equivalent dose" was invented to show how tiny most scare-story numbers are.
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Gray and sievert are not interchangeable
For x-rays and gamma rays 1 Gy gives 1 Sv, but alpha particles are 20 times more damaging for the same energy. Converting between them needs the radiation type.
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Background
About radiation units
The gray measures energy absorbed per kilogram. The sievert weights that by how much harm the radiation type does, which is what health limits use. The US still reports rem, a hundredth of a sievert.