Flight Radiation Calculator

The average cosmic radiation dose rate at cruising altitude is roughly 3–6 μSv per hour, depending on altitude and latitude. A 10-hour transatlantic flight at mid-latitudes typically delivers around 30–60 μSv — comparable to 3–6 chest X-rays. Polar routes receive more radiation than equatorial ones due to weaker geomagnetic shielding at high latitudes.

A sievert (Sv) is the SI unit measuring the biological effect of ionizing radiation on the human body. Because everyday doses are tiny, we use microsieverts (μSv) — one millionth of a sievert — or millisieverts (mSv), one thousandth of a sievert. The annual radiation limit for the general public recommended by the ICRP is 1 mSv (1,000 μSv) above natural background.

1 mSv is the annual dose limit set by the International Commission on Radiological Protection (ICRP) for the public from artificial sources. At this level, the increased lifetime cancer risk is estimated at about 0.005% — extremely small. Occasional flight doses are well within safe limits; however, frequent flyers and aviation crew who accumulate doses above 6 mSv/year are monitored under occupational radiation guidelines.

Earth's magnetic field deflects cosmic rays most effectively near the equator and least effectively near the poles. Polar and sub-polar routes, such as flights over Greenland or Alaska, therefore receive significantly higher cosmic ray flux. A New York–London polar route can deliver roughly 50–80% more radiation than an equivalent-duration equatorial flight.

Yes — significantly. Cosmic radiation intensity increases with altitude as there is less atmosphere to absorb it. At 35,000 ft (typical commercial cruising altitude), dose rates are roughly 100–200 times higher than at sea level. A higher-altitude flight at 40,000+ ft (as flown by some business jets) can deliver meaningfully higher doses than a standard commercial flight.

No. Modern airport body scanners use millimeter-wave radio frequencies or very low-energy X-rays. The dose from a full-body security scan is in the range of 0.015–0.88 μSv — far less than the 3 μSv you receive during just one hour of flight. The security scanner contributes a negligible fraction of your total travel radiation exposure.

For most travelers, occasional flight radiation poses no meaningful health risk. Pregnant women are advised by ICRP to keep their total radiation exposure below 1 mSv during pregnancy; a few long-haul flights could approach this if routes are polar and at high altitude, so moderation is sensible. Aviation crew who fly more than 500–600 hours per year can accumulate doses of 2–6 mSv annually and are classified as occupationally exposed workers in many countries.

Natural background radiation at sea level is about 2,400 μSv (2.4 mSv) per year. A dental X-ray delivers ~5 μSv, a chest X-ray ~20 μSv, and a CT scan of the chest ~7,000 μSv. A 10-hour flight typically delivers ~30–60 μSv — less than three chest X-rays, and only about 1.5–2.5% of your natural annual background dose.