Flight Radiation Calculator

Aircraft occupants receive cosmic ionizing radiation. The dose for a particular flight depends on its route and conditions. The FAA's CARI-7 program calculates effective dose for an aircraft flight using a flight path and altitude information. It accounts for geographic location, changes in altitude, and changes in Earth's magnetic field and solar activity. CARI-7A offers additional research options.

Obtain a dose for your route from an appropriate external source, check that its result is an effective dose in µSv, and enter that number above. This page does not run CARI-7, read a flight plan, or estimate dose from flight time, altitude, or a polar-route label.

A dose from one trip is not automatically transferable to another. Route, latitude, altitude profile, flight duration, date, and space weather can affect the result. The FAA explains that CARI-7 can use waypoint-defined or shortest-route paths and can account for the time of a specific flight. A single fixed µSv-per-hour rate cannot represent all of those inputs.

If flights have different externally obtained doses, calculate each group separately and add the group totals. Record the source, route, date, and units alongside each figure so a later total can be checked.

Enter one externally obtained dose in microsieverts (µSv) and the positive whole number of one-way flights to which it applies. The calculation is dose per flight × number of flights. A millisievert (mSv) equals 1,000 µSv, so divide the total µSv by 1,000 to express the same amount in mSv.

For an illustrative arithmetic example, if an external source reports 20.5 µSv for a flight and four flights have that same dose, 20.5 × 4 = 82 µSv, or 0.082 mSv. The 20.5 µSv input is a demonstration value, not a typical dose or a prediction for any route.

You may use a decimal comma or point. The calculator requires a finite, nonnegative dose and a positive whole flight count; it rejects totals outside its numeric range. A return journey usually has two one-way flights, but use one multiplier only if the same source dose reasonably applies to both directions.

The result is arithmetic on the dose you supplied. It does not include other radiation sources, judge whether a trip is safe, or compare anyone with a legal or occupational limit. Such limits depend on the person, setting, jurisdiction, and type of dose.

The NIOSH guidance on aircrew and reproductive health discusses work exposures for flight attendants and pilots, including cosmic radiation and other job hazards. Its findings concern aircrew; they do not supply a universal passenger threshold or a pregnancy verdict from this calculator's total. For a personal or workplace assessment, consult the relevant occupational health or medical professional with your source data.

Can I enter flight duration instead of dose?

No. Duration by itself does not identify the route, altitude profile, date, or space-weather conditions used to determine dose. Get a dose from a route-specific source first.

Can I use this to evaluate pregnancy or aircrew duty?

No. This tool only sums entered values. The NIOSH material concerns aircrew reproductive health and explicitly notes uncertainty about safe exposure levels for every pregnant crewmember.

Sources and dates

• FAA, CARI-7 and CARI-7A: program capabilities and input factors; page updated September 28, 2026; accessed September 29, 2026.
• NIOSH, Aircrew and Reproductive Health: aircrew-specific context; published September 11, 2024; accessed September 29, 2026.

Related aviation tools: nautical mile converter for route distances and crosswind calculator for wind components. Neither supplies a radiation dose.