Normal oxygen level by age is usually the same for most healthy children and adults: 95% to 100% SpO2 at rest. Newborns are the main exception, since a level around 90% to 95% can be normal in the first minutes after birth before rising into the usual range.

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Quick Scoop

For most people, oxygen saturation does not change much by age, and a reading under 95% is often considered lower than normal. Some sources note that older adults may run a little lower, but below 90% is generally not normal and should be checked by a clinician.

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Age guide

Age group Typical normal SpO2
Newborns 90% to 95% at first, then quickly rises
Children 95% to 100%
Teens and adults 95% to 100%
Older adults Often still 95% to 100%, though some sources note slightly lower values may be seen

When to worry

A resting reading below 95% can be abnormal, and a reading below 90% is more concerning. If oxygen stays low or drops suddenly, it can signal a lung, heart, or circulation problem and should be medically evaluated.

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Bottom line: For most ages, normal blood oxygen is 95% to 100%, with newborns being the main exception.

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