Half a litre at a time
You took your first breath within seconds of being born and have taken one every few seconds since, almost all of them without thinking. At around 15 breaths a minute an adult breathes more than 20,000 times a day. Each relaxed breath moves about half a litre of air, so a single day of breathing adds up to more than ten thousand litres, enough to fill a small room. The circle above grows and shrinks at the pace you set, so you can feel what your own rate is like and, if you want, slow it down.
Try setting the slider to six breaths a minute and following the circle for a minute. Slow, even breathing like this is used in many relaxation techniques, and most people find it noticeably calming.
How we calculate it
Breathing rate changes a lot through childhood, so we use typical resting rates by age: 40 breaths a minute for the first year, 25 from one to five, 20 from six to twelve, and your chosen rate from thirteen onward. We multiply each rate by the minutes spent at that age. For the air total we multiply breaths by a typical tidal volume, half a litre for adults and less for children. Exercise makes you breathe faster and sleep slower, so treat the totals as friendly estimates.
| Age | Typical resting rate | Breaths a day |
|---|---|---|
| Newborn to 1 | 30 to 60 | about 57,600 at 40 |
| 1 to 5 | 20 to 30 | about 36,000 at 25 |
| 6 to 12 | 18 to 25 | about 28,800 at 20 |
| Adult | 12 to 20 | about 21,600 at 15 |
Worked example. A 36-year-old who breathes 15 times a minute: the first year adds about 21 million breaths, ages one to five about 66 million, six to twelve about 74 million, and the adult years about 186 million. That is roughly 346 million breaths. Because children move less air per breath, the air total comes to about 126 million litres.
Air you share
Every breath you take is a mix of nitrogen, oxygen and a little argon and carbon dioxide. Air is about 21% oxygen and the air you breathe out is still around 16% oxygen, so your body uses only a small share of what you take in. The rest goes back into the room, which is one reason a mouth-to-mouth breath can still help someone in trouble.
Questions people ask
How many breaths a minute is normal?
For a healthy adult at rest, about 12 to 20 breaths a minute. Babies breathe much faster, around 30 to 60 a minute, and the rate slows through childhood.
How much air is in one breath?
A relaxed breath moves about half a litre of air in and out, called the tidal volume. A deep breath can move several litres.
Does slow breathing help you relax?
Many people find that slowing to around six breaths a minute feels calming, and it is the basis of several relaxation techniques. The guide circle on this page can be set to that pace.
How much oxygen do we actually use?
Air is about 21% oxygen, and we breathe out air that is still about 16% oxygen, so only a fraction of each breath is used.
Sources. Typical resting respiratory rates and tidal volume from Cleveland Clinic and standard physiology texts; air composition from NASA. Calculations run in your browser; nothing you enter is sent anywhere.