Can Dexcom sensors be calibrated?

All Dexcom products can be calibrated, but not required. All our systems are designed to work properly without calibrations. Calibration is therefore an optional function.

When would I need to perform an optional calibration?

At times your Dexcom sensor may read up to 20% different from fingerstick readings and this is considered normal. If your Dexcom sensor is reading between 20% and 30% different from fingerstick then you may wish to try calibrating.

The no code option is only available on G6. If you are using this option, then you will need to calibrate for the duration of the sensor.

Do not calibrate in these situations.

• There is pressure on the sensor: Don't calibrate if the sensor reading seems inaccurate because of pressure on the sensor. The sensor should recover on its own when the pressure is relieved.
• Unstable glucose: Calibration works best when your glucose is stable. Consider waiting to calibrate if your glucose is changing rapidly (for example, after meals or during/after exercise).
• Rapidly changing glucose values: If there is an up or down arrow on your device this tells you that your blood glucose is currently moving quickly. Wait until you have a horizontal arrow. Recheck and if you feel your Dexcom device is inaccurate a one of optional calibration can be done. If you do calibrate when you have an up of down arrow, the calibration may not be accepted, or it may ask you to recalibrate later. It may also cause a sensor to fail.
• Sensor Error: If your display device displays a message related to sensor error, do not calibrate your device. Wait until the sensor error message goes away before you calibrate again.
• Frequent calibrations of the Dexcom device (over-calibration) may cause exaggerated jumps and drops in blood glucose, especially under the situations mentioned above.

If you are using Dexcom one or Dexcom G7 there is the option to log your blood glucose without using it as a calibration. This is not an option on Dexcom G6. If on Dexcom G6 do not use the calibrate option as a method of recording your fingerstick values.

Only ever enter the value from your blood glucose machine as a calibration. Do not enter the value from your Dexcom CGM or any other device that is testing your interstitial glucose.

When calibrating make sure to :

• Clean hands: Wash your hands with soap and water and dry them. Do not use gel cleaners. Poorly washed hands are the cause of many meter errors.
• Enter within 5 minutes: Enter the calibration within 5 minutes of taking a fingerstick.
• Only use fingerstick meter values. Other sites may be less accurate
• Calibrate in one display device: Calibrate in one display device, even if you use both the app and receiver. The CGM wearable sends calibration information between them.
• Meter values: Only calibrate with BG meter values from 2.2 mmol/L to 22.2 mmol/L.
• Calibration Not Used alert: If you get a Calibration Not Used alert, take another fingerstick and calibrate again.

How do I calibrate my Dexcom device?

To calibrate your Dexcom ONE, Dexcom ONE+ or Dexcom G7 using your BG meter (optional):

• In the app, tap + in the Glucose or History tab.
• In the receiver, go to Menu > Event > Blood Glucose.
• Select Blood Glucose, then use as Calibration. Follow onscreen instructions to enter BG meter value as a calibration.

To calibrate your Dexcom G6 using your BG meter (optional):

• In the app, click on Settings > Calibrate > Enter the blood glucose and press save
• In the receiver, go to Menu > Calibrate > Enter blood glucose and press save