About the Flight Radiation Calculator
When you fly at high altitude, you are exposed to cosmic radiation — high-energy particles from outer space and the Sun. At cruising altitude (~35,000 ft / 10,700 m), the atmosphere provides far less shielding than at sea level, resulting in dose rates 75–150 times higher than on the ground.
How It Works
The calculator uses an exponential dose-rate model based on altitude, derived from international radiation protection guidelines (ICRP) and FAA data:
- Sea level dose rate: ~0.04 µSv/hr (0.004 mrem/hr)
- Dose rate at altitude: increases exponentially — roughly doubling every 1,500 m (5,000 ft)
- Cruising altitude ~35,000 ft (10,700 m): approximately 3–6 µSv/hr (0.3–0.6 mrem/hr)
- Maximum cap: 10 µSv/hr for very high altitudes
Units Explained
| Unit | System | Usage | Conversion |
|---|---|---|---|
| µSv (microsievert) | Metric (SI) | International standard, science, medicine | 1 µSv = 0.1 mrem |
| mrem (millirem) | American (Imperial) | FAA, US nuclear industry, older standards | 1 mrem = 10 µSv |
| mSv (millisievert) | Metric (SI) | Annual limits, medical imaging | 1 mSv = 1,000 µSv |
Reference Values
- Average annual background radiation: ~2,400 µSv/year (240 mrem/year)
- One chest X-ray: ~20 µSv (2 mrem)
- Transatlantic flight (8 hrs): ~40–50 µSv (4–5 mrem)
- NYC to London (7 hrs): ~35 µSv (3.5 mrem)
- ICRP occupational annual limit: 20,000 µSv/year (2,000 mrem/year)
- FAA crew annual limit: 20 mSv/year = 20,000 µSv/year
Who Should Be Aware?
- Frequent flyers & business travelers: If you fly more than 10–20 times per year, your annual flight radiation can reach a noticeable fraction of background radiation.
- Flight crew & pilots: Airline crew are classified as occupationally exposed workers under ICRP and FAA regulations.
- Pregnant travelers: The FAA recommends pregnant crew members limit exposure to 1 mSv (1,000 µSv) during the entire pregnancy. Pregnant passengers face minimal risk from occasional flights.
Risk Levels Used
- Very Low: Annual flight dose < 100 µSv (< 10 mrem) — comparable to a few days of background radiation
- Low: 100–500 µSv (10–50 mrem) — equivalent to 1–6 chest X-rays
- Moderate: 500–1,000 µSv (50–100 mrem) — about 20–40% of average annual background
- Elevated: 1,000–5,000 µSv (100–500 mrem) — frequent long-haul flyers; still well below occupational limits
- High: > 5,000 µSv (> 500 mrem) — applicable mainly to airline crew; monitoring recommended
Altitude Quick Reference
| Altitude | Feet | Approx. Dose Rate | Typical Use |
|---|---|---|---|
| 0 m | 0 ft | 0.04 µSv/hr | Sea level |
| 3,000 m | 9,843 ft | ~0.19 µSv/hr | Mountain city (Denver) |
| 8,000 m | 26,247 ft | ~1.4 µSv/hr | Low cruise altitude |
| 10,700 m | 35,105 ft | ~3.5 µSv/hr | Typical commercial cruise |
| 12,200 m | 40,026 ft | ~6 µSv/hr | High cruise / business jets |
Disclaimer
This calculator provides educational estimates only. Actual radiation dose depends on many factors including solar activity, latitude, route, and specific aircraft. For professional occupational dose assessment, use certified dosimetry services or tools such as CARI-7 (FAA) or EPCARD (EU).