# Best BG meter - "Precise" or "Accurate"? **URL:** \ **Category:** Tips, Tech & Gear\ **Tags:** accuracy, smbg, glucose-meter\ **Created:** [April 6, 2017, 7:15pm UTC](https://forum.fudiabetes.org/t/best-bg-meter-precise-or-accurate/371 "2017-04-06T19:15:58Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Eric](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/eric/32/9209_2.png) [@Eric](https://forum.fudiabetes.org/u/Eric)\ **Post date:** [April 6, 2017, 7:15pm UTC](https://forum.fudiabetes.org/t/best-bg-meter-precise-or-accurate/371/1 "2017-04-06T19:15:58Z")
**Best BG meter - “Precise” or “Accurate”?** Sometimes you may hear these two terms used interchangeably. What is the difference between **precise** and **accurate**? Here is a quick example that makes it easy to understand (_and doesn’t use a bunch of math terms like Mean Absolute Deviation (MAD), variance, or standard deviation that makes normal people’s eyes bleed._ 😄 ). * * * Suppose your blood sugar is currently 120. - If you test it multiple times and you see results such as 132 and 131, those results are more precise but less accurate. - If you test it multiple times and you see results such as 125 and 116, those results are more accurate but less precise. In the first example, the numbers were closer _to each other_, but farther from your _actual BG value_ of 120. More precise, but less accurate. In the second example, the numbers were closer to the _actual BG value_, but farther _from each other_. More accurate, but less precise. The image below shows the difference between accurate and precise: ![](https://canada1.discourse-cdn.com/flex030/uploads/fudiabetes/original/1X/72bd7a05729e2a6be1defa2d288ce644a96b2908.png) Obviously, a meter that is **BOTH** accurate and precise is the best. But which is better between accurate and precise? The answer may surprise you. That will be the topic of another post. ---
**Author:** ![lh378](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/lh378/32/601_2.png) [@lh378](https://forum.fudiabetes.org/u/lh378)\ **Post date:** [April 6, 2017, 8:17pm UTC](https://forum.fudiabetes.org/t/best-bg-meter-precise-or-accurate/371/2 "2017-04-06T20:17:59Z")
Thanks for sharing! ---
**Author:** ![docslotnick](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/docslotnick/32/75_2.png) [@docslotnick](https://forum.fudiabetes.org/u/docslotnick)\ **Post date:** [April 7, 2017, 4:02pm UTC](https://forum.fudiabetes.org/t/best-bg-meter-precise-or-accurate/371/3 "2017-04-07T16:02:22Z")
@Eric Excellent explanation! The target graphics give instant recognition of a difficult to explain difference. ---
**Author:** ![MM2](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/mm2/32/3032_2.png) [@MM2](https://forum.fudiabetes.org/u/MM2)\ **Post date:** [August 24, 2017, 8:21pm UTC](https://forum.fudiabetes.org/t/best-bg-meter-precise-or-accurate/371/4 "2017-08-24T20:21:24Z")
I remember a discussion on these terms in a freshmen engineering class. A clock that is always running 5 minutes late is more accurate then a clock with a dead battery. But the dead battery clock is more precise twice a day during the time where it is stuck. With BG testing, there are also human error or bad product factors that can also contribute. (Hmmm, as I recall the class on human factors, and the story we heard about the guys who got hurt when they lifted a lawnmower and tried to trim their bushes. There were no safety guards or warning labels to tell them not to do it, and they tried to sue the mfg. ---
**Author:** ![daisymae](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/daisymae/32/1199_2.png) [@daisymae](https://forum.fudiabetes.org/u/daisymae)\ **Post date:** [August 24, 2017, 10:48pm UTC](https://forum.fudiabetes.org/t/best-bg-meter-precise-or-accurate/371/5 "2017-08-24T22:48:19Z")
this is extremely helpful to me, with one exception: how do i actually know what my precise BG is before testing? for example, i test my BG on meter “A” and it reads 120. i test my BG on meter “B” and it reads 132. so i re-test on both meters. meter “A” says 127, while meter “B” reads 134. it would appear that i should trust Meter “B” b/c it seems consistent (only a 2 point difference). but then i come to find that my actual BG is 124. in your example, which i fully understand, it would be meter “A” that is more accurate and meter “B” which is more precise. so, how on earth, w/out a veinapuncture, would i know which meter reading to trust? is there a solution to this that i am missing? or is this something that you could do at your doctors office when they draw blood from your vein for your A1c? ---
**Author:** ![Chris](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/chris/32/382_2.png) [@Chris](https://forum.fudiabetes.org/u/Chris)\ **Post date:** [August 24, 2017, 10:51pm UTC](https://forum.fudiabetes.org/t/best-bg-meter-precise-or-accurate/371/6 "2017-08-24T22:51:55Z")
> [@daisymae](#): > > is this something that you could do at your doctors office when they draw blood from your vein for your A1c? Ding ding ding, this is the best answer. They also report you bg from that blood draw. You would use that. ---
**Author:** ![daisymae](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/daisymae/32/1199_2.png) [@daisymae](https://forum.fudiabetes.org/u/daisymae)\ **Post date:** [August 24, 2017, 11:03pm UTC](https://forum.fudiabetes.org/t/best-bg-meter-precise-or-accurate/371/7 "2017-08-24T23:03:39Z")
> [@Chris](#): > > They also report you bg from that blood draw. You would use that. thats exactly what i do. or, at least, thats what i would like to think that that is what i do 😉 ---
**Author:** ![Eric](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/eric/32/9209_2.png) [@Eric](https://forum.fudiabetes.org/u/Eric)\ **Post date:** [August 24, 2017, 11:23pm UTC](https://forum.fudiabetes.org/t/best-bg-meter-precise-or-accurate/371/8 "2017-08-24T23:23:06Z")
I am putting together a wiki on this topic. Here is the specific item for that particular subject: * * * 1. It is helpful validate your meter with a lab blood test. This is easy to do. When you are getting your lab tests done during your endocrinologist visit, right before they draw the blood you should check your BG with your meter twice. Write the numbers down! When you get your endocrinologist’s lab blood test results back, they will usually have the blood glucose value as part of the blood test panel they performed. Compare the lab BG value with the results you got from your meter right at the same time as the blood test (which is why you wrote those numbers down!). Those numbers should be close, particularly if you were in normal range. ---
**Author:** ![Thomas](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/thomas/32/1719_2.png) [@Thomas](https://forum.fudiabetes.org/u/Thomas)\ **Post date:** [August 25, 2017, 1:24am UTC](https://forum.fudiabetes.org/t/best-bg-meter-precise-or-accurate/371/9 "2017-08-25T01:24:51Z")
> [@Chris](#): > > They also report you bg from that blood draw. Ours does not. A1c only. ---
**Author:** ![Chris](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/chris/32/382_2.png) [@Chris](https://forum.fudiabetes.org/u/Chris)\ **Post date:** [August 25, 2017, 3:04am UTC](https://forum.fudiabetes.org/t/best-bg-meter-precise-or-accurate/371/10 "2017-08-25T03:04:42Z")
Wow, they must be using an in-office A1c without a blood draw. Every three months we get the full blood draw with all of the results. Different strokes… ---
**Author:** ![Sam](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/sam/32/10595_2.png) [@Sam](https://forum.fudiabetes.org/u/Sam)\ **Post date:** [August 25, 2017, 3:08am UTC](https://forum.fudiabetes.org/t/best-bg-meter-precise-or-accurate/371/11 "2017-08-25T03:08:18Z")
Usually serum glucose levels are only “truly” measured if they do serious labs like a comprehensive panel… if I was being charged for this without indication more than about once a year I’d be pretty pissed about it… ---
**Author:** ![Thomas](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/thomas/32/1719_2.png) [@Thomas](https://forum.fudiabetes.org/u/Thomas)\ **Post date:** [August 25, 2017, 12:26pm UTC](https://forum.fudiabetes.org/t/best-bg-meter-precise-or-accurate/371/12 "2017-08-25T12:26:35Z")
> [@Chris](#): > > they must be using an in-office A1c Correct. Fingerstick. Machine on the counter. About 5 mins for the results. ---
**Author:** ![Chris](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/chris/32/382_2.png) [@Chris](https://forum.fudiabetes.org/u/Chris)\ **Post date:** [August 25, 2017, 1:56pm UTC](https://forum.fudiabetes.org/t/best-bg-meter-precise-or-accurate/371/13 "2017-08-25T13:56:42Z")
> [@Sam](#): > > Usually serum glucose levels are only “truly” measured if they do serious labs like a comprehensive panel… if I was being charged for this without indication more than about once a year I’d be pretty pissed about it… We aren’t super happy about it, but it is their practice not ours. We are in an HMO, so no choice really. Fortunately the cost is only $5 extra per visit. But we do get a full panel every visit. ---
**Author:** ![Eric](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/eric/32/9209_2.png) [@Eric](https://forum.fudiabetes.org/u/Eric)\ **Post date:** [August 25, 2017, 2:01pm UTC](https://forum.fudiabetes.org/t/best-bg-meter-precise-or-accurate/371/14 "2017-08-25T14:01:40Z")
> [@Thomas](#): > > Correct. Fingerstick. Machine on the counter. About 5 mins for the results. Do they not actually stick a needle in a vein and draw any blood at all? ---
**Author:** ![Sam](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/sam/32/10595_2.png) [@Sam](https://forum.fudiabetes.org/u/Sam)\ **Post date:** [August 25, 2017, 2:39pm UTC](https://forum.fudiabetes.org/t/best-bg-meter-precise-or-accurate/371/15 "2017-08-25T14:39:56Z")
Nope… capillary blood sample just like a home bg test ---
**Author:** ![Eric](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/eric/32/9209_2.png) [@Eric](https://forum.fudiabetes.org/u/Eric)\ **Post date:** [August 25, 2017, 2:47pm UTC](https://forum.fudiabetes.org/t/best-bg-meter-precise-or-accurate/371/16 "2017-08-25T14:47:06Z")
> [@Sam](#): > > Nope… capillary blood sample just like a home bg test I understand for that fingerstick BG test, but I mean outside of that. Like they are not doing any kind of blood test panel. No standard complete blood count, no creatinine, no WBC and RBC count, no hematocrit, vitamin D. All those things. I don’t know if they never do those tests for kids, or just sometimes, or what. But if you are getting _any_ blood taken from a vein, it seems that glucose would be one of the things they would test - especially for a diabetic! ---
**Author:** ![Sam](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/sam/32/10595_2.png) [@Sam](https://forum.fudiabetes.org/u/Sam)\ **Post date:** [August 25, 2017, 2:49pm UTC](https://forum.fudiabetes.org/t/best-bg-meter-precise-or-accurate/371/17 "2017-08-25T14:49:00Z")
My doc orders real labs 1x yearly… and does an finger stick a1c every time I walk in the door ---
**Author:** ![Eric](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/eric/32/9209_2.png) [@Eric](https://forum.fudiabetes.org/u/Eric)\ **Post date:** [August 25, 2017, 2:54pm UTC](https://forum.fudiabetes.org/t/best-bg-meter-precise-or-accurate/371/18 "2017-08-25T14:54:34Z")
> [@Sam](#): > > My doc orders real labs 1x yearly Yes, so when they draw blood, is your current blood glucose included in the results of the panel? ---
**Author:** ![Sam](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/sam/32/10595_2.png) [@Sam](https://forum.fudiabetes.org/u/Sam)\ **Post date:** [August 25, 2017, 2:56pm UTC](https://forum.fudiabetes.org/t/best-bg-meter-precise-or-accurate/371/19 "2017-08-25T14:56:38Z")
Only if they order a “comprehensive metabolic panel” is your glucose level actually determined-- which is probably not selected every time… I’m not really sure how often it is. Glucose levels aren’t tested in CBC (shelly just corrected me). Vitamin d levels are a seperate and individual lab test… ---
**Author:** ![Eric](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/eric/32/9209_2.png) [@Eric](https://forum.fudiabetes.org/u/Eric)\ **Post date:** [August 25, 2017, 3:05pm UTC](https://forum.fudiabetes.org/t/best-bg-meter-precise-or-accurate/371/20 "2017-08-25T15:05:33Z")
> [@Sam](#): > > Only if they order a “comprehensive metabolic panel” which is probably not selected every time… I don’t always get blood drawn, but I figure if I have to go through the hassle, they might as well make it worth my while. So those are always part of the results I get. [Next page](https://forum.fudiabetes.org/t/best-bg-meter-precise-or-accurate/371.md?page=2)