Pulse Oximeter at Home: What It Measures and How to Use One

A fingertip pulse oximeter is a small, easy-to-use device that estimates the oxygen saturation of your blood (SpO2) and your pulse rate. Here is how it works and how to get a reliable reading at home.

What a pulse oximeter measures

The device shines light through your fingertip and measures how much is absorbed. It then displays an SpO2 percentage and a pulse rate in beats per minute.

How to get an accurate reading

• Rest for a few minutes and sit still with your hand at heart level.
• Remove nail polish or artificial nails from the finger you are using.
• Make sure your hand is warm, since cold fingers can give poor readings.
• Wait for the number to stabilise before noting it down.

What to look for when buying

• A clear, bright display that is easy to read.
• Fast reading time and automatic power-off to save battery.
• A comfortable fit for different finger sizes.

Browse our pulse oximeters and other health essentials.

This article is for general information only and is not medical advice. A home oximeter is not a diagnostic tool. If you feel unwell or are concerned about a reading, contact a healthcare professional.

Frequently asked questions

Can I use a pulse oximeter on any finger?

Most devices work on the index or middle finger. Follow the instructions that come with yours.

Why does my reading change?

Movement, cold hands and poor fit can all affect results. Try again once you are calm and warm.