Incentive Spirometer: What the Numbers Mean, How to Use It

Type the number the piston reached and the goal your team gave you, and see what it means. Below the answer is a counter for the routine — tap once after each breath, ten an hour. The goal is always your team’s; this page never makes one up.

⚠ Severe difficulty breathing, a tight chest, or blue or grey lips: call 999 (US: 911) — not more breaths. NHS · checked 2026-09-26

One breath on the column

1,250 mL — 83% of the 1,500 mL goal your team set250 mL to go. If you cannot make the piston rise to the number your healthcare provider set for you, it’s OK. Reaching your goal takes time and practice.

Slide the goal marker to 1,250 — level with the top of the piston, not the bottom — and try to match it next hour.

This page explains the device and counts your breaths. It is not a lung-function test, it does not set your goal, and it cannot tell you how your lungs are healing — your team can.

Instructions checked 2026-09-26.

Ten breaths an hour — the counter

Tap once after each breath — ten make a set.

Breathe in slowly, hold it for 3 to 5 seconds, breathe out — then tap. Ten taps make one set.

Quick answer: the big number the piston reaches is how much air you breathed in, in millilitres (mL and cc are the same). The small float beside it is not a score — it shows how fast you are breathing in, and it should stay between its two arrows. The slider is a marker you move yourself. The routine most hospitals teach is 10 slow breaths every hour you are awake, holding each for at least 3 to 5 seconds — and the number to aim for is set by your own team, not by your age on a chart.

How to use this page

To check a number, type where the top of the piston reached and, if you have one, the goal your team wrote down. You get the volume, how close it is to your goal, and where to put the marker. To do your breaths, switch to the counter and tap the big button once after each breath. After ten, it tells you when the next set is due — and it works that out from the clock, so it is still right if your phone locks in between. The sets you finish are kept in this browser only.

What the three moving parts mean

The piston in the tall column rises as you breathe in. Read the number level with its top, not its bottom — that is the volume of that one breath. 1,500 on the column means about one and a half litres.

The coaching indicator is the small float in the narrow window at the side. It measures speed, not size. Above the top arrow, you are breathing in too fast; below the bottom one, too slowly. Slow and steady is what the device is built to teach, which is why it has a speed gauge at all. Some models show speed with a ball or a “good, better, best” window instead of arrows; the leaflet in the box says which.

The goal marker is the slider on the side of the column. It does nothing by itself. Your team may set it for you before you go home; after each set, you slide it to the best you reached, so next hour you have something to match.

“What number should I be hitting for my age?”

There is no published target by age, and the tables of “adults under 40 should reach 3,000” you will find on shop pages have no publisher behind them. The number depends on your age, height and sex, and on the surgery you had and how you are healing — which is why the people who looked after you set it. Memorial Sloan Kettering tells its own patients that most people start with a goal of 500 mL and are asked to aim higher as they heal. Some boxes include the maker’s own chart; if your team did not give you a number, ask them rather than picking one from a chart.

And if you are not reaching the goal yet, that is normal in the first days. Pain, stitches and tiredness all hold a breath down. What matters is doing the breaths every hour and seeing the number creep up.

How exact is the number?

Less exact than it looks. The column is read by eye off a moving piston, and when researchers measured the same breaths on a common volume spirometer and a digital one at the same time, in 150 people aged 7 to 80, the two disagreed by up to about half a litre either way. So the number is a good way to compare your own breaths, on your own device, from hour to hour. It is not a lung-function test, and it is not worth comparing with a friend’s device or with the breathing test a hospital does.

Why your team may also ask you to cough and walk

The respiratory-care guideline behind the device does not recommend it on its own. It recommends it together with deep breathing, directed coughing, getting out of bed and moving early, and good pain relief. The spirometer is the part you can see; the walking and coughing are just as much part of the plan. If you had surgery on your chest or tummy, holding a pillow firmly against the wound while you breathe deeply or cough makes both easier.

When to stop, and when to call

If you feel dizzy or light-headed, take the mouthpiece out, take a few normal breaths and rest until it passes. Call your healthcare provider for chest or lung pain, severe pain on a deep breath, trouble breathing, coughing up blood, or fluid or blood from your wound when you cough. Severe difficulty breathing, a tight or heavy chest, or lips turning blue or grey is 999 or 911, not a reason to do more breaths.

Worked examples

1,250 with a goal of 1,500. 83% of the goal, 250 mL to go. Slide the marker to 1,250 and try to match it next hour.

1,600 with a goal of 1,500. Goal reached. Tell your team — they may move it up as you heal.

800 and no goal. That is 0.8 litres in one breath. This page will not tell you whether that is enough, because nobody can without knowing you and your operation; ask the team who gave you the device.

3,000 on a 2,500 column. Not possible — check that you read the number at the top of the piston, and on the big column, not the speed window.

FAQ

What do the numbers on an incentive spirometer mean?

They are the volume of one breath in, in millilitres (mL) or cubic centimetres (cc), which are the same. If the top of the piston reaches 1,500, you breathed in about one and a half litres.

What is a good incentive spirometer number for my age?

There is no official number by age. Your goal depends on your age, height and sex and also on the surgery you had and your recovery, so your healthcare team sets it. Many people start at around 500 mL and are asked to aim higher as they heal.

How often should I use my incentive spirometer?

The routine most hospitals teach is 10 slow breaths every hour you are awake, holding each for at least 3 to 5 seconds. Your own team’s instructions come first if they are different.

What does the small indicator on the side do?

It shows how fast you are breathing in. Keep it between the two arrows: above means too fast, below means too slow. It is not a second score.

Why do I feel dizzy when I use it?

Deep breaths one after another can do that. Take the mouthpiece out, take a few normal breaths, and rest before carrying on. Feeling dizzy or light-headed while using it is on Memorial Sloan Kettering’s list of reasons to call your healthcare provider, so tell them.

Can I use an incentive spirometer without having had surgery?

It is a medical device that is usually given for a reason — after surgery, an injury to the chest, or an illness that keeps you in bed. If you have been given one, use it the way your team explained. If you have not, and your breathing worries you, that is a conversation with your doctor rather than a device to buy.

Is the number on my spirometer accurate?

Accurate enough to compare your own breaths from hour to hour on the same device. In a 2026 study, a common volume spirometer and a digital one measuring the same breaths disagreed by up to about half a litre either way, so it is not a lung-function test.

Incentive Spirometer Guide & Breath Counter