βοΈ Flight Radiation Calculator
Cosmic dose from your flights, in plain millisieverts.
Estimated dose
How to Use This Calculator
Enter your total flight hours and pick the route type closest to your flying, then hit Calculate Dose. The headline is your estimated cosmic radiation dose in millisieverts; the details translate it into everyday comparisons: chest X-rays, days of background radiation, and share of the annual background. The default rate of 0.005 mSv per hour reflects typical cruising altitudes around 35,000 feet. Polar routes run higher because Earth's magnetic field steers cosmic rays toward the poles; short low hops run lower.
Total your flight hours for the trip or the year. A US cross-country leg is about 5 hours.
Pick the route type. Polar long-haul (like US to Asia over the pole) gets the +40% factor.
Hit Calculate Dose and read the comparisons, not just the raw number.
For crew-level annual totals, enter yearly hours to see occupational context.
The Method: Dose Rate Times Hours
The 0.005 mSv per hour figure is a mid-range estimate for cruising altitudes near 35,000 to 40,000 feet; published measurements span roughly 0.003 to 0.008 depending on altitude, latitude, and solar activity. Dose rate approximately doubles every 6,500 feet of altitude, which is why the number is negligible on the ground and measurable at cruise. Solar storms can spike rates temporarily, and airlines reroute polar flights during major events. The route factors are approximations: polar long-haul genuinely runs higher, short hops spend more time at low altitude where rates are lower. Treat the result as an order-of-magnitude estimate, which is all the health context requires.
Worked Example
A traveler flies New York to London and back: about 7 hours each way, 14 hours total, typical route. Dose = 14 x 0.005 x 1.0 = 0.07 mSv. That equals roughly 3.5 chest X-rays, about 8 days of natural background radiation, and just over 2 percent of the average American's annual background dose of 3 mSv. A pilot flying 800 hours a year on mixed routes: 800 x 0.005 = 4 mSv, inside occupational norms and tracked by regulators. Enter 14 hours above and the calculator reproduces the traveler's 0.07 mSv with the same comparisons.
Putting the Number in Context
Radiation fear thrives on numbers without denominators. The denominators: background gives you 3 mSv yearly without flying; a single CT scan gives 2 to 10 mSv; the occupational limit averages 20 mSv per year. A 0.05 mSv trip is 1.7 percent of background, the equivalent of moving from Miami to Denver for a few weeks (altitude raises background dose). Frequent flyers who log 200 hours a year add about 1 mSv, a third of background. These are the comparisons that turn an abstract worry into a proportion, and the proportion is small.
Limits of This Estimate
This is an educational estimate, not a dosimeter reading. Real dose varies with exact altitude profile, latitude, solar activity, and even the solar cycle phase. It does not account for security scanners (negligible dose) or medical exposures. Pregnant travelers and aircrew with specific concerns should consult their doctor or their airline's occupational health program rather than relying on a web calculator. The physics is well measured; your personal number is still an approximation.
Educational estimate only, not medical advice. Dose rates vary with altitude, route, and solar activity. Consult a doctor for personal health questions.
Frequent Flyers: Annual Dose in Context
Crew members are the real frequent flyers: pilots and flight attendants can accumulate 2 to 5 mSv per year, making them among the most radiation-exposed groups of workers, and airlines track it as an occupational exposure. For passengers, even 50 flights a year stays well under 1 mSv for most routes; the 1 mSv public guideline is a regulatory marker, not a danger threshold. Context helps: the average American's annual background dose is about 3 mSv from natural sources (radon, cosmic rays at ground level, food), a chest CT is about 7 mSv, and living in Denver adds roughly 0.5 mSv yearly versus sea level. Flight dose is a small fraction of these for occasional travelers. If you fly weekly for work, the calculator's annual tally is worth a glance, but the health conversation belongs with your doctor, not a web tool.
Pregnancy and Flying
Pregnant travelers ask about radiation often, and the numbers are reassuring: a single long-haul flight delivers about 0.01 mSv or less to the fetus, far below the 50 mSv level where guidelines suggest concern. The American College of Obstetricians and Gynecologists notes no increased risk from occasional flights. Frequent flyers who are pregnant (crew members especially) should discuss cumulative exposure with their obstetrician and their employer's occupational health program; some airlines offer schedule adjustments. The bigger flight concerns in pregnancy are blood clots on long flights (walk, hydrate, consider compression stockings) and airline policies: most carriers restrict travel after 36 weeks for single pregnancies. As always, this calculator estimates dose; medical decisions need your clinician.
Second Worked Example: The Weekly Commuter
A consultant flies 2 hours each way, 50 weeks a year: 200 flight hours. At a typical cruise dose rate of 3 microsieverts per hour, that is 200 Γ 3 = 600 microsieverts, or 0.6 millisieverts per year. Average natural background in the US is about 3.1 millisieverts per year, so the flying adds roughly 20 percent on top of background. It is measurable but small: one abdominal CT scan delivers about 8 millisieverts, more than 13 years of this commute. Enter your own hours above to see where you land.
Polar Routes and Solar Storms: When Dose Spikes
Not all flight hours are equal. Earth's magnetic field funnels cosmic radiation toward the poles, so a New York to Tokyo polar routing delivers a higher dose rate than an equatorial hop of the same length. Altitude matters too: dose roughly doubles every 6,500 feet of climb, which is why business jets at 45,000 feet see more than airliners at 35,000. Solar particle events, the strongest solar storms, can spike dose rates several times above normal for hours, though airlines reroute or lower altitude during the rare severe ones. These variations are why the calculator gives an estimate, not a dosimeter reading.
Crew Limits: The 20 Millisievert Line
Frequent flyers never approach regulatory limits, but aircrew do live under them. European rules classify aircrew as occupationally exposed workers, and international guidance (ICRP) recommends keeping crew dose under 20 millisieverts per year averaged over five years. A long-haul pilot logging 900 block hours can accumulate 3 to 6 millisieverts annually, comfortably under the line but far above any passenger. Pregnant crew members get a stricter 1 millisievert limit for the remainder of pregnancy, which is why airlines reassign expectant crew away from high-altitude polar routes. For passengers, even the heaviest travel schedule stays an order of magnitude below these occupational numbers.
The Banana Equivalent Dose
Radiation educators compare doses to bananas: one banana delivers about 0.1 microsieverts from its natural potassium-40. A 5-hour flight at 3 microsieverts per hour is 15 microsieverts, or 150 bananas. The comparison is silly and genuinely useful: it puts the flight's dose in the same category as eating fruit, which is to say, not a health decision. You would need to eat 150 bananas per flight for the fruit to match the flight, and the flight is still harmless.
Frequently Asked Questions
How much radiation do you get on a flight?
Roughly 0.004 to 0.006 millisieverts per hour at typical cruising altitude, so a 5-hour flight gives about 0.025 mSv. That is comparable to a few days of natural background radiation. Enter your flight hours above for the estimate, and compare it to the everyday exposures listed in the results.
Is flight radiation dangerous?
At normal travel levels, no. The doses are tiny fractions of regulatory limits: a frequent flyer logging 500 hours a year receives about 2.5 mSv, similar to natural background. Airline crew are monitored as radiation workers in some countries precisely because their cumulative dose is measurable but still well within safe limits.
Do pilots get too much radiation?
No. Long-haul crew accumulate roughly 2 to 5 mSv per year from cosmic radiation, and regulators in the EU and elsewhere track it as occupational exposure. Limits for radiation workers are 20 mSv per year averaged over five years, so crew doses sit comfortably below. This calculator shows how far typical travel falls short of those limits.
Is it safe to fly while pregnant?
Occasional flights are considered safe; the dose from a single trip is far below levels of concern. Frequent flyers who are pregnant sometimes discuss scheduling with their doctor as a precaution. This is general information, not medical advice: talk to your own doctor about your specific situation.
Why is there radiation on planes?
Cosmic rays from space constantly bombard the atmosphere, and at 35,000 feet there is far less air above you to absorb them. Dose rates roughly double every 6,500 feet of altitude gain. The plane's metal skin blocks almost none of it; altitude is the whole story.
Which flights give the most radiation?
Long, high, polar routes: a New York to Tokyo polar flight delivers more dose than an equatorial hop of the same length, because Earth's magnetic field funnels cosmic rays toward the poles. Higher cruising altitudes also increase the rate. The calculator uses an average rate; polar long-haul runs about 30 to 50 percent higher.
How does flight radiation compare to an X-ray?
A chest X-ray is about 0.02 mSv, roughly equal to 4 to 5 hours of flying. A cross-country US flight (about 5 hours) gives around 0.025 mSv. A CT scan is 2 to 10 mSv, equivalent to hundreds of flight hours. The results panel shows these comparisons so the number has context.
What is background radiation?
About 3 mSv per year for the average American, from radon, cosmic rays at ground level, soil, and food. It varies by location: Denver residents get roughly double the cosmic dose of sea-level Miami. One transatlantic round trip adds about 0.1 mSv, or roughly 3 percent of annual background.