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Gray/Rad & Sievert/Rem Unit Converter

Convert absorbed-dose units within the gray/rad family and dose-equivalent units within the sievert/rem family in separate sections.

Formula & worked example
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Calculator inputs

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How to use this calculator

Enter the known values in the units shown. Results update as you type.
Where results are editable, change one to solve backwards. Lock a value to hold it fixed.
Use the worked example to check the method. Reset restores the starting fields.

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Inputs and results stay in this browser tab. Bookify does not upload or store the values you enter.

Formula and method

1 Gy equals 1,000 mGy or 100 rad. Separately, 1 mSv equals 1,000 µSv or 0.1 rem. These identities do not convert absorbed dose into biological dose.

1 Gy = 100 rad; 1 Sv = 100 rem; milli = 10⁻³; micro = 10⁻⁶

Worked example

Enter these known values and leave the other values blank.

Same absorbed dose, initially grays: 1 Gy
Same equivalent-dose quantity, initially millisieverts: 1 mSv

Absorbed dose, initially milligrays: 1000 mGy
Same absorbed dose, initially rads: 100 rad
Equivalent-dose quantity, initially microsieverts: 1000 µSv
Same equivalent-dose quantity, initially rem: 0.1 rem

Assumptions and limitations

Absorbed-dose and equivalent-dose sections are independent. Gray and sievert quantities cannot be interchanged by a universal unit factor.
Values are nonnegative. These fields describe dose quantities, not dose rates; no per-hour or exposure-duration calculation is performed.
The optional BED display is only a fixed 0.1 µSv comparison unit. It does not estimate a food’s actual dose, risk, or biological effect.
A rem is a dose-equivalent unit. A roentgen is an exposure unit and is not interchangeable with a rem.

Common questions

Why does entering grays not fill sieverts?

They describe different physical or weighted quantities. Relating them requires additional radiation and tissue information, not just changing a prefix.

Does changing units tell me whether an exposure is safe?

No. This tool converts stated quantities; it does not evaluate exposure conditions, health effects or dose limits.

References

Bookify requires nonnegative quantities in this volume/mass, dose-unit or land-area conversion.

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