MedDroidSpO₂ (oxygen level) checker
Built by MedDroid · formulas from the British Thoracic Society oxygen guideline and the FDA (2021)
Free · no sign-up · runs in your browserEnter the SpO₂ percentage from your pulse oximeter to see what it means and what to do next. You also get tips for getting an accurate reading.
SpO₂ (oxygen level) checker
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Your result
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How it works
SpO₂ is the percentage of haemoglobin in your blood that is carrying oxygen, measured through the skin by a pulse oximeter.
This checker uses simple bands: 95 to 100% normal; 92 to 94% lower than usual, so recheck and see a doctor soon; below 92% see a doctor today; below 90%, or any reading with severe breathlessness, blue lips or confusion, is an emergency.
The British Thoracic Society suggests a target of 94 to 98% for most adults who are unwell, and 88 to 92% for some people with COPD. If your doctor has set your own target, follow it.
One reading can be wrong. A cold hand, nail polish, moving, poor fit and skin tone can all affect the number, so recheck and look at how you feel as well.
Related pages
Not a diagnosis. This tool gives a general estimate from a standard published formula. It is not a diagnosis and does not replace a check-up by a qualified doctor. If you feel very unwell, call your local emergency number (India: 108 or 112).
Frequently asked questions
What is a normal oxygen level?
For most healthy people, an SpO₂ of 95 to 100% is normal. It can be a little lower at high altitude or in people with long-term lung disease.
Is an SpO₂ of 94% bad?
It is a little lower than usual. Rest, warm your hands and measure again. If it stays at 94% or below, or you feel breathless, see a doctor soon.
When is a low oxygen level an emergency?
A reading below 90%, or any reading with severe breathlessness, blue or grey lips, confusion or chest pain. Call your local emergency number (India: 108 or 112).
Are pulse oximeters accurate on dark skin?
Studies have found that pulse oximeters can overestimate oxygen levels in people with darker skin tones. The US FDA issued a safety communication about this in 2021. Use the reading together with how you feel and other signs.