Convert Rad to Gray

Enter the number of rads that you want to convert to grays.

1 rad (rads) = 0.01 Gy (grays)

How to Convert Rads to Grays

The rad and gray are both units of radiation dose. By definition, 1 gray equals exactly 100 rads. This means to convert rads to grays, you divide by 100.

Formula

grays = rads ÷ 100

Step-by-Step Example

Convert 5 rad to grays:

1
Convert 5 rad to grays

We need to convert rads to grays

2
Apply the formula

Since 1 Gy = 100 rad, divide by 100

5 ÷ 100 = 0.05

Answer

5 rad = 0.05 Gy

Rad to Gray Conversion Table

Quick reference table for common rad to gray conversions. Click any value for detailed calculation.

Rads (rad) Grays (Gy)
1 rad 0.01 Gy
2 rad 0.02 Gy
5 rad 0.05 Gy
10 rad 0.1 Gy
15 rad 0.15 Gy
20 rad 0.2 Gy
25 rad 0.25 Gy
50 rad 0.5 Gy
100 rad 1 Gy

About These Units

Rad (rad)

The rad (Radiation Absorbed Dose) is the traditional unit of absorbed dose. One gray = 100 rads exactly. One rad = 100 ergs/gram = 0.01 J/kg. Still used in US medical and nuclear industries. One rad = one centigray = one rem for gamma/X-rays.

Gray (Gy)

The gray (Gy) is the SI unit of absorbed dose: energy deposited per unit mass (1 Gy = 1 J/kg). Named after Louis Harold Gray. For gamma/X-rays and beta particles, 1 Gy ≈ 1 Sv (quality factor Q=1). Radiation therapy total dose: 40-80 Gy.

Frequently Asked Questions

How do I convert rads to grays?

To convert rads to grays, divide the value by 100. For example, 10 rad = 0.1 Gy.

How many grays are in 1 rad?

1 rad equals 0.01 grays.

What is the formula for rads to grays?

The formula is: Gy = rad ÷ 100.