Radiation Converter

How these units are defined

One gray is one joule of energy absorbed per kilogram; the older rad is 0.01 Gy. One becquerel is one decay per second; the curie is exactly 3.7 × 10¹⁰ Bq.

Worked examples

• 1 Gray = 100 Rad
• 10 Gray = 1,000 Rad
• 100 Gray = 10,000 Rad

Common mistakes

• •Gray measures absorbed energy; the sievert measures biological effect (equivalent dose). They are only numerically equal for X-rays, gamma and beta radiation.
• •Becquerels describe how radioactive a source is, not the dose a person receives.

Radiation conversions

Sources for these factors

1. The International System of Units (SI Brochure), 9th edition — BIPM
2. Guide for the Use of the International System of Units (SP 811), Appendix B: conversion factors — NIST

Last reviewed 26 October 2026 against these sources. An automated check recomputes every factor from its definition on each build. How we check accuracy

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