Convert rad/second to gray/second (rad/s to Gy/s) easily. Learn the conversion formula, use our quick reference table, and understand the difference between traditional and SI radiation units.

Rad/Second to Gray/Second (rad/s to Gy/s) Conversion Guide

Welcome to our professional resource for converting rad/second (rad/s) to gray/second (Gy/s). If you are working with radiation therapy data, nuclear safety reports, or scientific research, you may need to switch between the traditional “rad” unit and the modern SI “gray” unit. This page provides the exact formula and context needed to ensure your dose rate calculations are accurate.

Contextual Information: Traditional vs. SI Units

Both the rad and the gray are units used to measure the absorbed dose of ionizing radiation—the amount of energy deposited in matter (such as human tissue) by radiation.

• rad (Radiation Absorbed Dose): The traditional cgs (centimeter-gram-second) unit of absorbed dose. While still used in some legacy systems and specific fields in the United States, it has largely been replaced in the international community.
• gray (Gy): The International System of Units (SI) derived unit for absorbed dose. One gray is defined as the absorption of one joule of radiation energy per kilogram of matter.
• Dose Rate (per second): Adding “/second” turns these into units of intensity, describing how quickly the radiation dose is being delivered.

The Conversion Formula

The relationship between these two units is fixed: 1 gray is exactly equal to 100 rads. Therefore, to convert from rads per second to grays per second, you must divide your value by 100.

Formula:

Gy/s = rad/s ÷ 100

or

Gy/s = rad/s × 0.01

Example Calculation: If a source delivers a dose rate of 250 rad/s, the conversion to gray/second would be: 250 ÷ 100 = 2.5 Gy/s.

A Conversion Table (Quick Reference)

Use the table below for rapid reference of common radiation dose rate conversions.

rad/second (rad/s)	gray/second (Gy/s)
1 rad/s	0.01 Gy/s
10 rad/s	0.1 Gy/s
50 rad/s	0.5 Gy/s
100 rad/s	1 Gy/s
500 rad/s	5 Gy/s
1,000 rad/s	10 Gy/s
5,000 rad/s	50 Gy/s

Why the Switch to Gray?

The transition from rad to gray is part of a global movement toward the SI system to ensure consistency in science and medicine across all borders. While the rad was convenient because 100 rads equaled 1 gray, the gray is now the mandatory unit for international peer-reviewed journals and regulatory agencies (like the IAEA). Converting rad/s to Gy/s allows for better collaboration between international medical and scientific teams.