What Is P95 on Your CPAP Report?

What Is P95 on a CPAP Report?

P95 on your CPAP report is the 95th percentile pressure: the pressure your machine stayed at or below for 95 percent of the night. Put another way, for all but the highest-pressure 5 percent of the night, your therapy pressure was at or under this number. It is a measured result of what your airway needed, not a setting you or anyone else dials in. ResMed reports it as the 95th percentile; Philips Respironics reports the same idea as the 90th percentile. It matters because it shows the pressure your machine actually worked at on a typical night, which is more useful than the single highest spike.

What P95 Actually Measures

An auto-adjusting machine (APAP) changes its pressure moment to moment as it detects flow limitation, snoring, and apneas. Over a night that produces thousands of pressure readings. Reporting one number from all of that is where percentiles come in.

Sort every pressure reading from the night from lowest to highest, then find the value that 95 percent of the night's readings fall at or below. That is your P95. A few brief spikes to a high pressure (for example, during a burst of events right before you woke up) sit in the top 5 percent and do not drag the P95 up, which is exactly why it is reported instead of the raw maximum. It answers a practical question: what pressure was my therapy really running at most of the night?

P95 vs. Median vs. Maximum Pressure

Your report usually shows three pressure numbers, and they answer different questions.

Number	What it means	What it tells you
Median (P50)	The middle pressure. Half the night was above it, half below.	Your typical resting pressure when things are calm.
P95 (95th percentile)	The pressure you were at or below 95% of the night.	The pressure your therapy needed to keep the airway open, headroom aside.
Maximum	The single highest pressure reached, even for a moment.	A brief peak, often one short event. Easily skewed by a single spike.

The gap between your median and your P95 is itself informative. A small gap means your pressure was steady all night. A large gap means the machine spent stretches of the night pushing well above your resting pressure to hold the airway open. Neither is automatically good or bad, but the pattern is worth understanding alongside your AHI and leak numbers.

Why ResMed Uses 95 Percent and Philips Uses 90

There is no universal standard, so manufacturers picked their own cutoff. ResMed AirView, myAir, and the AirSense and AirCurve machines report the 95th percentile. Philips Respironics DreamStation reports the 90th percentile. OSCAR, the open-source analysis tool, shows both so you can compare.

The practical effect: a Philips 90th percentile number will usually read a little lower than a ResMed 95th percentile would on the same breathing, because it excludes a larger slice of the high end. If you switch brands or compare notes with someone on a different machine, this is why the numbers do not line up one to one. It is a reporting choice, not a difference in the air you breathed.

What a Rising P95 Can Signal

Your prescription sets a pressure range, for example 4 to 20 cmH2O, and the machine moves within it. Your P95 shows where inside that range your therapy actually settled.

If your P95 sits comfortably below the top of your prescribed range, the machine has room to respond when your airway needs more. If your P95 creeps up toward the ceiling of your range night after night, the machine may be running out of headroom to treat your events. That is not something to adjust yourself, and it is not a verdict on whether your therapy is working. It is a specific, concrete observation you can bring to your sleep physician, who can look at whether your range needs revisiting. Tracking P95 over weeks, rather than reacting to one night, is what makes the trend meaningful. Our guide to CPAP pressure settings walks through the full picture of how these numbers relate.

P95 Is Measured, Not Set

A common point of confusion: P95 is not the same as your pressure setting. If your machine is set to a fixed pressure (straight CPAP rather than APAP), your P95 will simply equal that setting, because the pressure never changes. On APAP, your P95 is the machine reporting back what it chose, based on your breathing. So a P95 that differs from your prescribed minimum is normal and expected on an auto machine. If a comfort feature like EPR is on, it lowers pressure during exhale but does not change how P95 is calculated from the therapy pressure.

Where to Find Your P95

Most reports surface it under a heading like "Pressure" or "Therapy pressure," alongside your median and maximum. On ResMed, the full number lives in the AirView clinician report rather than the simplified myAir app. OSCAR shows it on the daily details view. If you want to see your P95 next to your AHI, leak, and a plain-English read of the night, you can upload your SD card data to CPAP Clarity and it stays in your browser. For the wider tour of every number on a therapy report, see how to read your CPAP data.

Common Questions

What does P95 mean on a CPAP machine?

P95 means the 95th percentile pressure: the pressure your machine stayed at or below for 95 percent of the night. It reflects the pressure your therapy actually needed on a typical night, ignoring brief high spikes.

What is a good P95 pressure?

There is no single "good" number, because it depends on your prescribed range and your body. What providers generally look at is whether your P95 sits within your prescribed range with room to spare, rather than pressed against the ceiling. Your prescribed range and your sleep physician are the reference points, not a universal target.

Is P95 the same as my pressure setting?

Not on an auto machine. On APAP, your setting is a range and P95 is the measured result of what the machine chose within it. On fixed CPAP, P95 equals your set pressure because the pressure does not vary.

Why is my P95 different from my Philips friend's?

ResMed reports the 95th percentile and Philips Respironics reports the 90th percentile. The Philips number excludes more of the high end, so it tends to read slightly lower for similar breathing. It is a difference in how the report is calculated, not in the therapy.

Does a high P95 mean my CPAP is not working?

No. A high P95 by itself is not a verdict. It shows the machine worked at a higher pressure to keep your airway open. What is worth a conversation with your provider is a P95 that keeps climbing toward the top of your prescribed range, because that suggests the machine may be short on headroom.

Putting Your P95 in Context

P95 is the pressure your CPAP actually delivered most of the night, reported as the 95th percentile so a few brief spikes do not distort it. Read it alongside your median pressure, your prescribed range, and your AHI to understand your night, and bring a P95 that trends toward the top of your range to your sleep physician rather than changing anything yourself.