How to Do Box Breathing: A Simple Step-by-Step Guide

Box breathing is one of the most well known breathing techniques for a reason. It is simple, it builds focus, and it trains your relationship with two of the most powerful tools in breathwork: breath holds and CO2 tolerance. If you are new to the wider subject, our guide to what breathwork is sets the scene, but you do not need any background to start here.

The technique is built from four equal parts: an inhale, a hold, an exhale, and a second hold, all the same length. Because those four equal phases map onto the four sides of a box, it is called box breathing.

In this guide we walk through what box breathing is, why the two breath holds matter so much, and exactly how to practise it step by step, including why the second hold feels harder and how long each count should be.

What is box breathing?

Box breathing (also called square breathing or, in military settings, tactical breathing) follows a repeating four count rhythm: inhale for a count, hold for the same count, exhale for the same count, hold again. A common starting pattern is four seconds per phase, which works out to a full breath cycle of about 16 seconds, or roughly four breaths per minute. That is well inside the slow breathing range associated with a calmer, more focused state.

The part I love most about this one is that it includes two breath holds: one on the inhale and one on the exhale.

Why the breath holds matter

Breath holds are incredibly powerful for the nervous system. As kids we used to hold our breath all the time, but as adults we tend to forget about this. The holds are where a lot of the benefit lives.

One of the main things they train is your tolerance to CO2. Carbon dioxide is the primary chemical driver of your breathing. It is what tells your brain when to take the next breath. If you are very sensitive to CO2, your breathing rate climbs and your breath gets shallow and quick. Gently training that tolerance through breath holds helps you stay smooth and steady rather than reactive to the feeling of “air hunger.”

The steady, even rhythm is also why box breathing is so often cited for focus. It is famously used by Navy SEALs. Retired SEAL commander Mark Divine named the technique and taught it as a way to slow the breath and deepen concentration under pressure, and the same 4-4-4-4 pattern appears in military training as “tactical breathing.”

The research on slow breathing more broadly backs up the calming effect. A 2018 systematic review in Frontiers in Human Neuroscience found that slow breathing techniques increase heart rate variability and parasympathetic (“rest and digest”) activity, and are linked to increased relaxation and reduced anxiety. Box breathing itself was one of three breathing patterns tested in a 2023 Stanford randomised controlled trial, where five minutes a day for a month improved mood and reduced physiological arousal more than mindfulness meditation did. Worth being precise about the result: all three breathing patterns helped, and cyclic sighing, which uses a long extended exhale, produced the largest improvement of the three.

How to do box breathing, step by step

1. Get into a comfortable position

Get yourself into a nice, relaxed state. Positioning matters more than people think. When box breathing feels tight, it is often because there is tension in the chest. Try not to be too arched in your back. Tilt your tailbone in slightly, and you should naturally feel able to breathe into the lower parts of your lungs more effectively. Stay relaxed rather than stiff. The whole point of this practice is a relaxed, focused state. It might feel a bit effortful at first, but once you find your rhythm you will start to forget anything is even happening.

If it is hard to keep track of which phase you are on, use a timer. That is exactly why we built one into Remindful.

2. Start with the inhale

The inhale can be stiff, so slow it down. Think of it as air falling into your nose rather than something you force. As you breathe in, move the breath through your body in order: belly, ribs, chest, head.

3. Hold at the top

On that first hold, really let it find its stillness. Then start your count there.

4. Release into the exhale

Slowly release into the exhale and focus on relaxation washing over you as the breath leaves.

5. Hold at the bottom

When you reach the bottom of the exhale, add a gentle hold. This one tends to be more challenging for most people, and there is a good reason for it (below).

Then repeat the cycle.

Why the exhale hold feels harder

The hold at the bottom of the exhale is usually tougher than the hold at the top, and that is completely natural. Here is the mechanism: when you hold on empty lungs, you have a much smaller reserve of air to draw from, so CO2 in your blood climbs toward the “air hunger” threshold faster than it does when you hold on full lungs. Less buffer, faster signal.

So keep your box breathing count consistent with what feels sustainable on the exhale hold, not the inhale hold. Do not force the exhale hold. If you push it, you can tip yourself the other way and actually trigger the stress response, leaving you feeling panicked rather than calm. Ease is the goal.

How long should each count be?

Start with a count of 4. If that feels too easy, you can build up to a count of 5. If you are new to this, do not push past 5. Let your tolerance grow gradually over time. Remember, this is about diaphragm control and your tolerance to CO2, not about how long you can white knuckle a hold.

A quick note on safety

Box breathing is safe for most healthy people. Because it involves breath retention, if you are pregnant or have a cardiovascular or respiratory condition, check with your doctor before practising the holds. Never do breath holds in or near water, or while driving.

If you enjoy the count based structure of box breathing, the other well known technique in this family is 4-7-8 breathing, which leans on a long exhale rather than equal phases.

If you would like to practise box breathing with guidance, we run private one-on-one sessions and group sessions, and the Be Remindful app includes a built in timer and a daily practice you can use anywhere.