Flight Radiation Calculator
Enter your flight duration and route type to see your estimated cosmic radiation dose in microsieverts and millisieverts. The result is compared to everyday medical exposures, the US average annual background dose, and the ICRP aircrew occupational limit. The steps panel shows the full calculation, and the chart below lets you trace how dose grows with flight hours.
Why do you receive radiation during a flight?
Earth is constantly bombarded by high-energy particles from space called galactic cosmic rays. At ground level, the atmosphere provides thick shielding that absorbs most of them. When you fly at cruising altitude - typically 30,000 to 40,000 feet (9,000 to 12,000 m) - you are above most of that shielding, and the dose rate is roughly 50 to 100 times higher than at sea level. The intensity grows further at high latitudes, because the geomagnetic field is weakest near the poles and provides less deflection of incoming particles. Transatlantic and transpolar routes therefore carry higher dose rates than short, low-latitude hops.
How is flight radiation calculated?
The standard approach is to multiply a route-specific dose rate (in microsieverts per hour, uSv/h) by the block time in the air. Dose rates are measured by dedicated instruments on board aircraft and published by agencies including the FAA, the UK Health Security Agency, and European research programs such as EPCARD. Typical published rates range from about 3 uSv/h on a short tropical flight to around 6-7 uSv/h on a transatlantic crossing and up to 8-10 uSv/h on the most extreme polar routes. The effective dose you receive is the rate multiplied by hours aloft, expressed in microsieverts (uSv) or millisieverts (mSv). One millisievert equals 1,000 microsieverts. For context, the average American receives about 6.2 mSv of total background radiation per year from all sources combined.
Dose limits for aircrew and frequent flyers
The International Commission on Radiological Protection (ICRP) sets an occupational limit of 20 mSv per year averaged over five years (with no single year exceeding 50 mSv) for radiation workers, and airlines classify flight crew as occupationally exposed under most regulatory frameworks. By contrast, the general public limit is 1 mSv per year above background. An occasional traveler taking a handful of long-haul flights a year will typically accumulate 0.5-2 mSv from flying - well below both limits. Frequent flyers and crew on the most exposed polar routes can approach 2-5 mSv annually, still typically within occupational limits. During pregnancy, the ICRP recommends keeping the embryo or fetus below 1 mSv over the full gestation period; a single transatlantic flight contributes roughly 5% of that limit.
Is flight radiation dangerous?
At the doses received on typical air travel, the added cancer risk is extremely small. Epidemiological studies of flight crew - the most exposed group - have not found convincing evidence of increased solid-tumour incidence attributable to cosmic radiation alone, though some studies suggest a modest elevation in melanoma risk that is likely confounded by UV exposure and lifestyle factors. The dose from a transatlantic return trip (roughly 0.1 mSv) is smaller than the dose from a single chest CT scan (roughly 8 mSv) and is dwarfed by natural background. For most travelers, other in-flight health considerations, such as dehydration, prolonged sitting and jet lag, are far more significant than radiation.
Radiation dose comparison table
| Source | Approx. dose | Equivalent dental X-rays |
|---|---|---|
| Background (hourly average, sea level) | 0.0003 mSv | 0.06 |
| Dental X-ray | 0.005 mSv | 1 |
| Transatlantic flight (8 h) | 0.048 mSv | ~10 |
| Chest X-ray | 0.10 mSv | 20 |
| Mammogram | 0.40 mSv | 80 |
| Aircrew annual dose (typical) | 2-5 mSv | 400-1000 |
| Abdominal CT scan | 8 mSv | 1600 |
| ICRP aircrew occupational limit | 20 mSv/year | 4000 |
| US NRC whole-body public limit | 1 mSv/year | 200 |
| ICRP pregnancy limit (gestation) | 1 mSv | 200 |
Approximate effective doses for common sources. All values are for reference and vary with equipment, protocol and individual factors.
Frequently asked questions
How much radiation does a transatlantic flight give you?
A typical New York to London flight of about 7-8 hours at a dose rate of roughly 6 uSv/h delivers around 40-50 uSv (0.04-0.05 mSv). The return trip doubles that to about 80-100 uSv - still less than 2% of the average annual US background dose of 6.2 mSv. A chest X-ray (about 100 uSv) is a useful comparison point.
Does flying increase your cancer risk?
At typical passenger doses, the extra lifetime cancer risk is extremely small. For a transatlantic round trip giving roughly 0.1 mSv, a standard linear no-threshold model implies a risk increase of about 5 in a million - far below everyday risks and well within the range where any effect cannot be distinguished from statistical noise. Long-term studies of aircrew, who are the most exposed group, have not established a clear link between cosmic radiation and increased solid-tumour rates beyond what is explained by lifestyle and other occupational factors.
Is flying safe during pregnancy?
For most pregnant travelers, occasional air travel is considered safe. The ICRP recommends keeping fetal exposure below 1 mSv over the entire gestation. A single transatlantic flight contributes roughly 0.05 mSv - about 5% of that limit. Problems can arise only with very frequent long-haul flying during pregnancy. Most major obstetric and aviation medical organizations agree that occasional leisure or business flights are acceptable, but pregnant flight crew are usually offered route changes to limit cumulative exposure.
Do pilots and flight attendants get dangerous radiation doses?
Flight crew are the occupational group with the highest average cosmic radiation exposure in many countries - typically 2-5 mSv per year, compared with the ICRP occupational limit of 20 mSv/year. Those flying the most polar routes most frequently can approach 5-8 mSv annually, but this remains below the regulatory limit. Airlines in Europe and other jurisdictions are required to monitor and manage crew dose under aviation radiation protection regulations.
Why does latitude affect the dose rate?
Earth's magnetic field acts as a shield that deflects incoming cosmic ray particles. The field is strongest at the equator and weakest at the poles. At high latitudes, this deflection is reduced, and more particles penetrate to aircraft cruising altitude. This is why a polar route carries a dose rate roughly 2-3 times higher than an equatorial route flown at the same altitude.
What units are used to measure radiation dose?
Effective dose - the standard measure for health risk from radiation - is measured in sieverts (Sv). Because flight doses are very small, they are typically quoted in microsieverts (uSv, one millionth of a sievert) or millisieverts (mSv, one thousandth of a sievert). One mSv equals 1,000 uSv. The dose rate in flight is expressed in uSv per hour or mSv per hour.