Dr. David Taylor, MD, PhD · Last reviewed April 28, 2026

Pulse Oximeter Reading Chart

Type your SpO2 reading and instantly see the band, what it means, and what to do — adjustable for COPD baseline, high altitude, newborns, athletes, and children. Save readings to an in-browser log; export a clinician-ready PDF.

Pulse oximeter reading interpreter

Healthy adult at rest, sea level.

Enter your pulse oximeter SpO2 reading between 0 and 100 percent.

Enter your SpO2 reading above to see what band it falls in and what to do.

SpO2 bands for this context

Adult

Each band is shown at equal visual width for clarity — actual numeric ranges are noted on each cell.

For educational reference only. This tool helps you interpret a pulse oximeter reading you have already taken — it does not measure SpO2 and is not a substitute for clinical assessment. Pulse oximetry can be inaccurate in low perfusion, with nail polish, in carbon monoxide poisoning, or in dark skin tones (FDA 2024 guidance). If your reading is below 90%, you have new shortness of breath, chest pain, blue lips/fingertips, confusion, or you feel unwell at any reading, seek medical care.

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How to use this chart

  1. Pick the right context at the top of the tool. Most adult readings stay on the default. Switch to COPD if you have a chronic-lung diagnosis with a prescribed home-oxygen plan, High altitude if you're above ~5,000 ft, Newborn only for the first 10 minutes of life, Athlete if your resting heart rate runs in the 40–60 range, or Child for ages 1–12. Each context shifts the bands and the pulse-rate norms — a 91% reading is "mild concern" for an adult but "within baseline" for someone with COPD.
  2. Type your SpO2 reading in the left field — just the number, no percent sign. Optionally enter your pulse rate on the right. The result updates instantly. The colored band on the right side of the result card tells you the tier: green (safe), amber (monitor), orange (contact clinician same-day), or red (urgent / emergency).
  3. Read the guidance and the band visualization. The horizontal color bar below the inputs shows where your reading falls across all five bands for the chosen context. The little black diamond marks your number.
  4. Save the reading if you're tracking SpO2 over time (post-COVID recovery, COPD home-oxygen titration, sleep-apnea monitoring, altitude acclimatization). Add an optional note like "after walking up stairs" or "morning, before breakfast" for context.
  5. Download or share the log when it's time for a clinic visit. The PDF lists chronological readings with timestamps, context, band, and notes — formatted to hand directly to a pulmonologist or primary-care provider.

What the bands mean (and how this differs from a single chart)

Most pulse-oximeter charts you'll find online — including the one near the top of MedicineNet's article and the static PDFs from NHS practices — are one-size-fits-all. They show "95–100% normal, below 90% hypoxemia" and that's it. The number that matters depends on who you are, where you are, and what's happening in your body.

Adult (default)

For a healthy adult at sea level: 95–100% is normal. 91–94% is the mild-concern zone — usually fixed by a few minutes of calm rest or by warming a cold finger. Below 90% (hypoxemia) is the threshold the CDC/NHLBI use to flag a reading as clinically concerning. Below 80% is severe and below 70% is a true emergency.

COPD baseline

The American Thoracic Society recognizes that patients with stable COPD may have a baseline of 88–92% — and that's "normal" for them, especially if they're on a prescribed home-oxygen plan. Treating an 89% reading from a COPD patient like an 89% reading from a healthy 30-year-old leads to either unnecessary panic or, occasionally, missed deterioration. This tool's COPD context shifts the bands so the colors map to your actual baseline.

Newborn (first 10 minutes only)

Newborns transition from placental to pulmonary circulation across the first 10 minutes of life. Per the AAP Neonatal Resuscitation Program, expected SpO2 rises from ~60% at 1 minute to 85–95% at 10 minutes. After that, the same target as any other child applies (95% +). The newborn context is for those first 10 minutes only — not for ongoing pediatric monitoring.

High altitude

At sustained altitudes above ~5,000 ft (Denver, Albuquerque, ski resorts, the Andes, Himalayan trekking), normal SpO2 shifts down to about 90–95%. A 90% reading at 8,000 ft is not the same warning as a 90% reading at sea level — but a sustained drop combined with headache, breathlessness at rest, or nausea can signal acute mountain sickness or, more dangerously, high-altitude pulmonary edema (HAPE). The altitude context flags the difference and points toward descent + evaluation when the number drops below the altitude-adjusted threshold.

Trained athlete

SpO2 thresholds are the same for athletes as anyone else, but resting heart rate bands differ — endurance athletes routinely rest at 40–60 bpm, which is bradycardia in an untrained person but normal for them. The athlete context tells the pulse-rate display not to flag a 50 bpm resting rate as concerning when paired with a normal SpO2.

Child (1–12 years)

SpO2 targets match adults (95–100%), but children's normal pulse-rate range runs higher: roughly 70–120 bpm at rest for ages 1–10. A child's 110 bpm at rest isn't tachycardia.

Three real-world examples

COPD baseline at home

Marian, 68, has GOLD-stage 3 COPD and uses 2 L/min of supplemental oxygen at home. Her pulmonologist's plan: target 89–92% on oxygen, contact the office if she drops below 87% for two consecutive readings. She switches the tool's context to COPD, types 90, and the band shows green ("Within COPD baseline — monitor"). Two days later her morning reading is 86%; she switches to COPD context, sees the orange "Below your baseline" band and tier label "Contact your provider," logs the reading, repeats in 10 minutes (86% again), and calls her pulmonologist's office before lunch — exactly what the action plan said. Without context-aware bands, the same 86% would have looked alarming or, in the other direction, an 89% would have looked alarming.

Post-COVID recovery tracking

Daniel, 41, recovered from a moderate COVID infection three weeks ago but still notices breathlessness on stairs. He starts taking spot SpO2 readings: morning at rest, mid-day, and after a brief walk. He keeps the context on Adult. Most readings come back 96–98% (Normal, green). One afternoon he gets 92% after a half-mile walk; the band shows amber "Mild concern — Monitor closely." He logs it with the note "after walking 0.5 mi, slight breathlessness," rests 5 minutes, and re-tests. The recheck reads 96%. A week of logs goes to his primary care visit — the trend (normal at rest, modest exertional drops) plus a paired peak flow log drives the conversation toward pulmonary rehab rather than a CT scan.

Sleep apnea screening

Aiyana, 52, snores and wakes up tired. She has no oximeter at night, but during a daytime nap her partner uses a continuous overnight oximeter (a model her doctor mentioned) and downloads the trace. Several dips into the 86–88% range catch her attention. She enters one of the dips into this tool — Adult context, 87% — and reads "Moderate hypoxemia, contact your clinician same day." She brings the trace plus the SpO2 log to her primary care provider, gets a sleep-study referral, and is diagnosed with moderate obstructive sleep apnea. The oximeter didn't diagnose anything; it produced the data that triggered the right referral. (Continuous overnight tracking is what most spot-check oximeters can't do — see our pulse oximeter review for models that include overnight reports.)

What affects accuracy

A pulse oximeter shines red and infrared light through a fingertip and infers SpO2 from how the colors change. That's elegantly simple — and it has known failure modes that anyone using one at home should understand:

  • Low perfusion (cold fingers, Raynaud's, shock). Reduces the pulsatile signal, so the device may report an artificially low SpO2 or fail to lock on. Warm the finger for 30–60 seconds (rub it, run warm tap water), and recheck. If still low, try the earlobe (some oximeters support ear sensors) or another finger.
  • Nail polish (especially black, blue, dark green). Absorbs the wavelengths the sensor uses. Remove polish or rotate the sensor 90° so the light passes through skin instead of nail.
  • Motion. Tremor or shivering disrupts the signal. Sit still for 60 seconds before reading.
  • Ambient light. Bright sunlight or fluorescent overhead light can leak in. Cup your free hand around the sensor.
  • Carbon monoxide poisoning. CO binds hemoglobin so tightly the pulse oximeter can't distinguish CO-bound from oxygen-bound hemoglobin — and reports a falsely normal SpO2 in a patient who's actively dying. Headache, dizziness, and nausea after a closed-room exposure (gas heater, generator, car) warrant emergency care regardless of the SpO2 reading.
  • Skin pigmentation. Per FDA 2024 guidance, pulse oximeters can overestimate true SpO2 in people with darker skin — meaning a reading of 92% may correspond to a true value lower than that. If you have darker skin and your reading is in the 91–94% "mild concern" range with any symptoms, treat it as if it were a band lower and contact a clinician.

Frequently asked questions

What is a normal pulse oximeter reading by age?

For healthy adults and children (1+ years), normal SpO2 is 95–100%. For newborns in the first 10 minutes of life, 90–95% is part of the normal transition. Adults with stable COPD may have a baseline of 88–92% (per ATS guidance) — that's the COPD context in this tool.

At what oxygen level should I go to the ER?

SpO2 below 90% with any new symptoms (shortness of breath, chest pain, blue lips or fingertips, confusion, severe fatigue) warrants emergency evaluation. Below 80% is a clear emergency at any context. If your reading is below 80% and you're alone, call 911 — don't drive yourself.

Can I trust a $20 fingertip pulse oximeter?

For spot-checking SpO2 in the 92–100% range in a healthy adult with normal perfusion, the cheap fingertip oximeters sold on Amazon are accurate enough — most claim ±2% and clinical comparisons confirm that for the upper range. They get less reliable below 90%, in low-perfusion states, in dark skin, and during motion. For COPD home monitoring, post-surgical recovery, or anything where decisions ride on the number, an FDA-cleared device is worth the extra cost. See our guide to pulse oximeters for the FDA-cleared models we recommend.

Why does my reading change so much within a few minutes?

Real SpO2 doesn't change by 5% over a few minutes in a healthy person — but the measurement can, because of finger temperature, motion, sensor placement, and ambient light. If two consecutive readings disagree by more than 2%, take a third. Use the median of three readings. The trend across several days matters more than any single reading.

Can I embed this tool on my own site?

Yes — copy the embed snippet at the bottom of this page. The embedded version is a stripped-down variant designed for clinics, COPD support communities, sleep-apnea blogs, pulmonologist practices, and patient-education pages. Required attribution is built in. There is no fee, no signup, no analytics attached to the embed.

If you're tracking SpO2 at home — for COPD, post-COVID, sleep-apnea screening, altitude trips, or general wellness — these four product categories cover most needs. Each links to the full review with current top picks, prices, and pros/cons:

  • Best Pulse Oximeters — FDA-cleared fingertip and ring oximeters, including continuous overnight models for sleep-apnea screening.
  • Best Nebulizers — when SpO2 drops correlate with airway inflammation (asthma, COPD exacerbation, post-viral bronchitis), a nebulizer delivers bronchodilators and steroids directly to the lungs.
  • Best Peak Flow Meters — pairs naturally with SpO2; peak flow drops before SpO2 does in asthma, giving earlier warning.
  • Best CPAP Machines — for sleep apnea, the long-term fix once a sleep study confirms it. Some include built-in SpO2 tracking.

Sources & methodology

This tool is reviewed annually for citation currency. About Dr. Taylor · Last reviewed April 28, 2026.

Embed this tool on your site

Free for clinics, COPD support communities, sleep-apnea blogs, pulmonologist practices, patient-education sites, and personal blogs. Required attribution is included in the snippet. No fee, no account, no analytics. 

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