Why the need to take 2 readings to calibrate?

I was wondering what the point is of the two readings within 5 minutes to calibrate after startup… My reading only changed by 1 point…which seems kind of dumb!

I think the general idea of the two readings is to get a sense of what the glucose meters drift is, and see if you put in an off reading…
If theres too large of a skew between the two numbers, Iv seen the dexcom throw up an error…

I agree with you Jake. Since the BG meters can be off as much as 20%, it is good to give two readings so the CGM can work between the two and give a number that is probably more accurate.

Richard157 is very correct. Meters are only +/- 20% accurate. Two readings before your BG level changes much tells the receiver how sweet you really are. Keep in mind the way a Dexcom unit works is sugar in the fluid around your body cells creates a variable current in the sensor wire. The transmitter looks at the current, assigns a value and sends it to the receiver. The receiver takes the transmitter value, runs it through a calculation and overlays your finger sticks to display your curve.

Do not get frustrated. Sometimes I get two values the same. Other times they are in left field.

Thanks! I guess it makes sense, it just felt weird to test twice in a row haha.

My very first two readings were 96 and 136. Talk about a wake up call.