Free interactive tool
Convert a radiation dose rate between units and time bases, see what it means in context, and check acute-exposure timeframes. Everything runs here in your browser — no sign-up, nothing stored.
Enter a dose rate — for example a dosimeter reading in µSv per hour — and choose its unit and time base. You'll get the equivalent in every common unit, the hourly/daily/yearly rate, how it compares to background and medical doses, and a rough idea of acute-exposure timeframes.
Your input
Equivalent dose rate
| Unit | Per hour | Per day | Per year |
|---|---|---|---|
| mSv (as entered) | 1 | 24 | 8765.808 |
| µSv | 1000 | 24000 | 8765808 |
| mSv | 1 | 24 | 8765.808 |
Unit equivalents (per hour)
In context
Acute whole-body exposure
| Whole-body dose | Rate held constant | With 7-10 decay |
|---|---|---|
| Cumulative reference (500 mSv) | 20.8 days | not reached |
| Mild ARS — ~1 Sv (<5% mortality) | 41.7 days | not reached |
| Moderate — ~3 Sv (~5–50% mortality) | 125 days | not reached |
| Severe — ~6 Sv (~50–100% mortality) | 250 days | not reached |
| Almost certainly fatal — ~8 Sv | 333.3 days | not reached |
Time of continuous exposure to reach each whole-body dose. Rate held constant is the simple dose ÷ rate view, assuming the reading never changes. With 7-10 decay treats the reading as the 1-hour reference rate for fresh fallout decaying as t−1.2, with exposure beginning at H+1: the rate falls while you're exposed, so the dose converges — staying indefinitely accumulates at most 5 mSv, and any threshold above that is never reached. Real outcomes also depend on shielding, medical care and individual factors — for education only, and the t−1.2 rule holds for roughly the first six months after the blast.
Fallout decay from this initial reading
A rough projection using the practical “7-10 rule”: roughly every sevenfold increase in time after detonation, the dose rate falls by about tenfold.
0.001 rem = 1 mrem = 0.01 mSv
0.01 rem = 10 mrem = 0.1 mSv
0.1 rem = 100 mrem = 1 mSv = 0.001 Sv
1 rem = 1000 mrem = 10 mSv = 0.01 Sv
10 rem = 100 mSv = 0.1 Sv
100 rem = 1000 mSv = 1 Sv (sievert)
1000 rem = 10 Sv
1 R = 1 rad = 1 rem = 0.01 Sv = 10 mSv = 10 mGy
0.001 rad = 1 mrad = 0.01 mGy
0.01 rad = 10 mrad = 0.1 mGy
0.1 rad = 100 mrad = 1 mGy = 0.001 Gy
1 rad = 1000 mrad = 10 mGy = 0.01 Gy
10 rad = 100 mGy = 0.1 Gy
100 rad = 1000 mGy = 1 Gy (gray)
1000 rad = 10 Gy
Related tools — estimate your everyday annual dose with the personal dose estimator, model a single isotope with the isotope decay calculator, or plan time against a dose limit with the stay-time & dose budget tool.