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Grays to Rads Converter

Enter the absorbed radiation dose in grays below to convert it to rads.

Convert Grays to Rads

Enter a value in grays (Gy) to convert to rads (rad).

Result
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500rads
5 Gy = 500 rad
Result updates automatically
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Suggested Conversions
Reference:NIST OWM (SI Units — Length)
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Gray to Rad Conversion Table

Table showing various gray measurements converted to rads. Click any preset value or arrow to load it into the converter.

How to Convert Grays to Rads

To convert grays to rads, multiply the absorbed radiation dose by the following conversion ratio: 100 rads/gray.

Since one gray is equal to 100 rads, you can use this simple formula to convert:

rads = grays × 100

The absorbed radiation dose in rads is equal to the absorbed radiation dose in grays multiplied by 100.

For example, here's how to convert 5 grays to rads using the formula above.

rads = (5 Gy × 100) = 500 rad

How Many Rads Are in a Gray?

There are 100 rads in a gray, which is why we use this value in the formula above.

1 Gy = 100 rad|1 rad = 0.01 Gy

Our gray to rad calculator automatically converts your absorbed radiation dose measurements with full decimal and scientific precision across US customary, imperial, and SI metric standards.

Grays and rads are both units used to measure absorbed radiation dose. Keep reading to learn more about each unit.

What Is a Gray?

SI derived unit of absorbed radiation dose (1 Gy = 1 J/kg = 100 rad). It serves as a primary reference unit for measuring absorbed radiation dose across scientific and practical applications. [1]

The gray is classified as an International System of Units (SI) unit of absorbed radiation dose. Grays can be abbreviated as Gy; for example, 1 gray can be written as 1 Gy.

As the primary coherent reference unit for absorbed radiation dose in this category, all other absorbed radiation dose units are mathematically anchored to the gray (Gy).

In practice, grays (Gy) are widely used across standard absorbed radiation dose applications within International System of Units (SI) workflows, engineering documentation, and technical data sheets.

What Is a Rad?

A rad is a unit of absorbed radiation dose equal to 1/100 of a gray (0.01 Gy). CGS absorbed dose unit equal to 100 erg/g or 0.01 Gray (1 cGy). [2]

The rad is classified as a standard unit of absorbed radiation dose. Rads can be abbreviated as rad; for example, 1 rad can be written as 1 rad.

When working with rads (rad) in formulas or technical specifications, always verify whether your target system uses SI metric, US customary, or British imperial standards.

In practice, rads (rad) are widely used across fine-tolerance laboratory, analytical, and micro-scale absorbed radiation dose measurements within international standard workflows, engineering documentation, and technical data sheets.

When converting absorbed radiation dose between grays (Gy) and rads (rad), keep full floating-point precision (1 Gy = 100 rad; 1 rad = 0.01 Gy) during intermediate calculations and round only the final rad figure to match your instrument tolerance.

More Gray & Rad Conversions

Need to calculate in the opposite direction? Use our rads to grays calculator to switch your starting unit immediately. You can also explore related tools such as converting rads to grays, converting grays to centigrays, or converting grays to milligrays.

Frequently Asked Questions

There are 100 rads (rad) in 1 gray (Gy). Conversely, 1 rad (rad) is equal to 0.01 grays (Gy).

References

NIST · BIPM · ISO
  1. [1]
    NIST OWM (SI Units — Length)·Radiation-Absorbed Dose Metrology Standard — Grays (Gy) to Rads (rad)
    NIST OWM Standard
  2. [2]
    BIPM (SI Base Unit: Metre (m))·Unit Specifications: Gray (Gy) & Rad (Radiation Absorbed Dose) (rad)
    BIPM Specification
  3. [3]
    NIST HB 133 (NIST Handbook 133 (2019 Ed.))·Conversion Factors & Mathematical Basis (Gy to rad)
    NIST HB 133 Reference
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