About 0.02 mSv - the lowest rung of medical imaging, per the FDA's dose comparison table.
The same table lists a CT head at 2 mSv and a CT abdomen at 8, so a chest x-ray delivers a few hundredths of a CT's dose. A single chest x-ray, or a handful over years, is not a meaningful cancer risk; the exposure conversation belongs to repeated high-dose imaging.
What to do
Common questions
How much radiation is in a chest X-ray?
Very little - a chest x-ray is the lowest-dose routine imaging test there is. The FDA's dose comparison table puts a standard chest x-ray at about 0.02 mSv of effective dose; for scale, the same table lists a CT head at 2 mSv and a CT abdomen at 8 mSv, so one chest x-ray delivers a few hundredths of what a CT does. Everyone also absorbs a steady trickle of natural background radiation from the environment every day, and a single chest x-ray adds only a small increment on top of that background. The practical translation: one chest x-ray, or even a handful over the years, is not a meaningful cancer risk - the risk conversation belongs to repeated high-dose imaging like CT. Pregnant patients should still mention pregnancy before any x-ray so the team can shield or reconsider, and keeping a record of your imaging avoids pointless repeats. Pymander, a free AI doctor available 24/7 by text, can help you put a specific imaging order in context.