roentgens, R

Medium

Result, rem0.965315519 rem1 R = 0.009653 Gy ·Soft tissue, w_R = 1Estimate for photon radiation — R is defined for X/gamma. The medium factor holds for gamma ~0.1–3 MeV; below 100 keV it is rougher. Not valid for alpha/neutrons.

Cross-family dose conversions (Sv↔Gy↔R) are estimates that depend on radiation type and medium (w_R, µ_en/ρ); conversions within one family are exact. Verify against accredited methods for official decisions.

How to convert roentgens to rem

For gamma radiation in soft tissue 1 R = 0.965316 rem. Enter a number above — the conversion uses this factor.

The roentgen is the exposure dose unit, defined for photons (gamma, X-ray). Conversion to absorbed and equivalent dose depends on the medium: for air 1 R ≈ 0.00876 Gy, soft tissue ≈ 0.0096 Gy, water ≈ 0.0097 Gy. It does not apply to alpha or neutron radiation.

For a different medium or other units, open the full dose converter: the medium (air, tissue, water) is selected explicitly, plus sievert, rem, gray, rad and roentgen.

Examples: 1 R = 0.965316 rem; 10 R = 9.65316 rem; 100 R = 96.5316 rem; 1,000 R = 965.316 rem. Reverse: 1 rem = 1.03593 R.