Rad to Gray Converter

How it is calculated

Enter a dose and choose the direction. The conversion is a single fixed factor: Gy = rad / 100 and rad = Gy × 100, because 1 Gy is exactly 100 rad. Rad to gray is the default direction. Gray results are shown with four decimals and rad results with two decimals, followed by the unit. Any number is accepted, including zero or negative values, which keep their sign. Since the gray result is rounded to four decimals, very small doses are shown as 0.0000 Gy even though they are not zero: 0.0003 rad (3 microgray) comes out as 0.0000 Gy, so for tiny doses convert in the Gy to rad direction instead. This tool converts absorbed dose only. It does not convert to sieverts or rem, which also depend on the type of radiation.

Common mistakes

• Choosing the wrong direction and getting a result 10,000 times off: 450 entered as gray and converted to rad gives 45,000 rad, not 4.5.
• Treating rem or sievert figures as rad or gray. Equivalent dose in rem or Sv includes a radiation weighting factor, so they are not interchangeable with absorbed dose in rad or Gy.
• Dividing by 10 instead of 100 (or confusing the gray with the centigray). A centigray equals one rad, so 450 cGy is the same as 450 rad, i.e. 4.5 Gy.
• Reading 0.0000 Gy for a very small rad value as zero dose. The output has only four decimals, so tiny doses are rounded away.