MEASUREMENT & METHODS

Rads (absorbed dose) (rad): absorbed dose unit guide

Understand rads (absorbed dose) (rad) for absorbed dose. Check base-unit equivalents, examples, comparison tables and source conventions.

What is being measured?

Absorbed dose is deposited energy per mass. It is not the same quantity as equivalent dose or a clinical interpretation.

rad means radiation absorbed dose here, not radians. Absorbed dose does not directly convert to equivalent dose without radiation weighting.

Meaning of rad

Rads (absorbed dose) uses the symbol rad in this library and measures absorbed radiation dose. Under the stated reference convention, 1 rad = approximately 0.01 Gy. This equivalence changes how a known value is written. It does not increase measurement accuracy or establish whether a measurement is appropriate to a real application.

Conversion method

Multiply the value by the source factor (0.01), then divide by the target factor (1). The factor ratio expresses the same absorbed radiation dose measurement in the other unit.

Worked example

For a known value of 10 rad, the reference conversion gives 0.1 Gy. Converting that result back gives approximately 10 rad. This reverse check helps catch a reversed factor, but matching round-trip arithmetic alone does not independently verify a source definition.

Common reference values

Input (rad)Reference equivalent (Gy)
10.01
50.05
100.1
250.25
500.5
1001

Compare one rad with other units

Target unitEquivalent of 1 radDefinition guide
Grays (Gy)0.01Read definition
Milligrays (mGy)10Read definition
Micrograys (µGy)10000Read definition
Kilograys (kGy)0.00001Read definition
Nanograys (nGy)10000000Read definition

Precision and common mistakes

  • Keep the source and target quantity consistent. A matching symbol is not enough to establish a compatible definition.
  • Record the original measurement precision. Showing twelve significant digits in a table does not make a rounded input more precise.
  • Check symbol capitalization, prefixes and any regional convention in the source. Use the displayed unit definition rather than a similarly named unit.
  • Factors involving repeating fractions or π use finite numerical precision. Round the final answer to the precision justified by your input.

Unit reference only. These pages do not assess biological effects, clinical use, exposure limits or radiation safety. Absorbed dose, equivalent dose, activity and exposure remain different quantities; unit scaling cannot convert one into another.

Use a working converter

Source and verification scope

Examples and tables are computed from the versioned unit definitions used by the linked converters. The source access dates appear below. Computandum is independent of the cited organizations; a citation does not mean that a publisher endorses this page or an actual project.

Sources

Read the calculation and sourcing methodology →