Estimate cosmic radiation exposure from flights based on route, altitude, and flight time. Compare doses to annual limits and medical scans.
At cruising altitude (35,000-45,000 feet), you receive 2-10 microsieverts per hour of cosmic radiation — 40-100× the rate at sea level. The Earth's atmosphere and magnetic field normally shield us, but commercial aviation puts you above most of that protection. This calculator estimates your radiation dose based on flight duration, altitude, and route latitude.
Latitude matters significantly: the magnetic field funnels cosmic rays toward the poles, so a New York–London flight delivers about 60% more radiation per hour than a Miami–Cancún flight of the same duration. Solar storms can temporarily double or triple the dose rate.
For the occasional traveler, flight radiation is negligible compared to annual background exposure (~3.1 mSv from natural sources). But frequent flyers logging 100,000+ miles per year, airline crew, and pregnant travelers should be aware of cumulative doses. The FAA classifies airline crew as radiation workers, and many airlines track crew exposure. Check the example with realistic values before reporting.
Most travelers don't think about flight radiation, but frequent flyers, airline crew, and pregnant travelers benefit from knowing their cumulative exposure. This calculator puts doses in context against medical procedures and annual limits. Keep these notes focused on your operational context. Tie the context to the calculator’s intended domain. Use this clarification to avoid ambiguous interpretation.
Dose per flight ≈ flight hours × dose rate (µSv/hr). Dose rate depends on altitude, latitude, and solar cycle. Typical rates: equatorial 35,000ft = 2.5 µSv/hr, mid-latitude 35,000ft = 4.5 µSv/hr, polar 40,000ft = 8 µSv/hr. Annual dose = dose per flight × flights/year.
Result: 58 µSv per flight, 700 µSv (0.70 mSv) annually — like 7 chest X-rays
Polar route at 39,000 ft ≈ 8.3 µSv/hr. 7 hours × 8.3 = 58 µSv per flight. 12 flights × 58 = 700 µSv annually, equivalent to about 7 chest X-rays.
Cosmic rays are high-energy particles (mostly protons) from outside the solar system. Earth's atmosphere absorbs most of them by sea level, but at cruise altitude (10-12 km), about 20-30% of the radiation is "secondary" particles created by cosmic ray interactions in the upper atmosphere. This includes neutrons, which are particularly biologically effective.
The International Commission on Radiological Protection (ICRP) recommends a 1 mSv/year limit for the public and 20 mSv/year for occupational exposure. The FAA's advisory (AC 120-61B) recommends that air carriers inform crew about radiation exposure and take measures to limit it, particularly for pregnant crewmembers.
Single dental X-ray: 5 µSv. Chest X-ray: 20 µSv. Mammogram: 400 µSv. CT head: 2,000 µSv. CT abdomen: 8,000 µSv. Annual background (US avg): 3,100 µSv. A frequent flyer doing 100 flights per year: 2,000-5,000 µSv additional.
For occasional travelers, no. A cross-country US flight gives about the same dose as a chest X-ray (25-50 µSv). Annual background radiation is about 3,100 µSv from all sources, so a few flights add only a small percentage. Concern increases with very frequent flying.
Commercial pilots typically receive 2-5 mSv per year, with international long-haul pilots at the higher end. This is below the 20 mSv/year occupational limit but above the 1 mSv/year public limit. The FAA classifies aircrew as occupationally exposed.
Yes, significantly. Polar routes (North Atlantic, transpolar) receive 60-100% more cosmic radiation than equatorial routes at the same altitude. Higher latitudes have less magnetic shielding, allowing more cosmic rays through.
The American College of Obstetricians recommends limiting fetal dose to under 1 mSv during pregnancy. Most occasional flying is fine, but frequent long-haul flying (especially polar routes) can approach this limit. Discuss with your doctor if you fly frequently while pregnant.
Yes. Each 6,000 feet of additional altitude roughly doubles the dose rate. A flight at 41,000 ft receives about 50% more radiation than the same route at 35,000 ft. Business jets flying at 45,000+ ft receive even more.
During severe solar particle events, radiation at flight altitudes can spike to 10-100× normal levels. Airlines monitor space weather and may reroute or lower altitude during events. The largest recorded events could deliver several mSv in a single flight.