BAC Calculation help.

Convicted Driver Insurance

LFCfan

Member
Hi. First off this website has been a great help since I joined, Thanks.

Can anyone tell me if the BAC calculators are roughly accurate? I know this is a very difficult question but basically when I put my accurate information in the calculator the result is 0.056 of alcohol in my blood. This is after drinking 5 drinks over 6.5 hours at my weight, age etc. I am a regular drinker and had not eaten since 3.5 hours before my first drink. When blood was taken at 01.45am in the station it was approx one hour 45 minutes since my last drink. (Large swig of 4% lager). I am praying my result is under the limit! Can anyone give me an idea or has anyone had similar circumstances? Thanks, really worried.
 
The BAC gives a reasonable indication, but as you say... A rough indication. It can be used when looking back, as you are, but should NEVER be used to look forward and predict when you will be just under the limit.
What you have posted though does not even qualify as a rough description of what your situation is..... 5 drinks could be anything from 5 to 30 units. When did you start drinking? Were you breath tested and if so, at what time (roadside and police station) and what were the results?
Looking again at what you have put, did you start drinking at 5.30pm? Did you accept a part of the blood sample? If so, the easiest way to be sure quickly is to get that analysed yourself at an independent lab.
 
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Hi, thanks for reply. So.. First drink at 7.15pm. Last drink finished at 11.45pm. Breath was 51 at roadside at 00.00. Blew 49 at station at approx 00.30. Blood taken at station at 01.45. (6.5 hours after first drink) Total drinks was 2 x 4.8% lager bottles (500ml) and 3 x 4% 440ml cans lager (5 drinks). Short break between 7.35 - 8.15pm with around half litre of water drank. Two hour gap between last drink and blood taken. I am male, 33, 177lbs, 5ft 10", regular drinker, nothing to eat since 03.45pm. BAC calculator on this website shows 0.056 with these details. I am hoping my results are under 0.080, feel slightly encouraged at the several calculators I have used which all say I should be under, just, solicitor and Police have said it is going to be close. I was hoping somebody could advise if they were in similar circumstances etc. I am so worried and can not really focus on anything else, this is going to be a long 6 weeks wait! Never again! Any advice is appreciated, Thanks!
 
I am not too comfortable with your calculations.
i am abroad ATM, so cannot use the online calculator, but can I suggest that you run those drinks through it again and see what reading it gives you for 12.30am. You know that your reading was 49 in breath then, which is the equivalent of 112 in blood. Does the calculator show 112? If ist shows less, then you have probably under estimated what you drank.
I would very much doubt that your reading would drop from 112 to 56 in an hour and a quarter, in fact I would expect it to drop from 112 to 92, and with the deduction of 6 that the lab do, result in a reading on 86 in the end. You say you are a regular drinker. This can result in faster elimination of alcohol, but your quoted drinking does not seem to indicate that you eliminated what you drank faster than average. Even if we speed up your elimination by 25% for the calculation, that would give a final reading of 81....... Anything over 80 is prosecution.
either way, I fear it is going to be much more like over 80 than a reading of 56.
 
Thanks again for reply. I can guarantee I had 5 drinks all night, starting at 07.13pm (phone call history). Two 500ml bottles of lager @ 4.8% between 07.13 & 08.00. Then no drink for around 45 mins at least, whilst i drank water. I then had three cans of Fosters (440ml @ 4%) from 08.50 and my last mouth full was approx 11.45. I was breathalysed at midnight whilst reversing my car around 30 feet to my drive (bad luck but no excuse). Blew 51 so was arrested and taken to Police station and then blew 49 lowest reading. This was around 00.45 at the latest. I then waited for blood to be taken which happened at 01.49. Two hours after last drink finished. I was drinking slow. Apart from my first two drinks, the three cans were consumed at approx 1 can per hour. I do not drink drive, i regularly leave my car or arrange taxi's etc. But I obviously will deal with this accordingly and do not condone drink driving. Sensitive subject but I do not feel I should lose pretty much everything I have worked for because of this, but it is the law that decides so what can I (we) say? I know its a hard calculation but does 5 drinks at my specifications mean I am over the limit? BAC calculators are varying between 0.056 to 0.078. I dont know what else to do, I am beside myself. Two kids, rely on my car, mortgage, job, like most of us.... Cant believe this is happening! I am not an irresponsible drink driver, hope I can keep my job! Thanks for any advice!
 
It is not easy predicting what the result of blood samples will be, any your latest post has muddies things.even more....
you said that you gave a a blood sample at 0145, but then varied it to 0149 - hardly any difference but 4 minutes is likely to have reduced your reading by 1 on the blood result. That could reduce it from 81 to 80, which is not above the limit so NFA.
BUT, you have then said that the breath test was at 0045 (latest) against your earlier thought that it was at 0030, so if 0045 is correct then that would reduce the time that you had for your body to eliminate alcohol, so that would ADD 4 to the final result, making a likely reading of 84 rather than 81 I originally said, or 89 if you eliminated alcohol at a normal - not enhanced rate.
Can you do what I suggested in my first response, as I still cannot access the online calculator until the weekend: put your drinks into the online calculator, and see what it says for your readings at 0030 and 0045, then see if either one shows 49, which was your police station reading. If, as I suspect, it shows a lower reading predicted, then you had more drinks, or the alcohol content was higher than you thought. The other possibility would be that you still had some alcohol in your system from an earlier drink at lunchtime?
 
price1367 said:
It is not easy predicting what the result of blood samples will be, any your latest post has muddies things.even more....
you said that you gave a a blood sample at 0145, but then varied it to 0149 - hardly any difference but 4 minutes is likely to have reduced your reading by 1 on the blood result. That could reduce it from 81 to 80, which is not above the limit so NFA.
BUT, you have then said that the breath test was at 0045 (latest) against your earlier thought that it was at 0030, so if 0045 is correct then that would reduce the time that you had for your body to eliminate alcohol, so that would ADD 4 to the final result, making a likely reading of 84 rather than 81 I originally said, or 89 if you eliminated alcohol at a normal - not enhanced rate.
Can you do what I suggested in my first response, as I still cannot access the online calculator until the weekend: put your drinks into the online calculator, and see what it says for your readings at 0030 and 0045, then see if either one shows 49, which was your police station reading. If, as I suspect, it shows a lower reading predicted, then you had more drinks, or the alcohol content was higher than you thought. The other possibility would be that you still had some alcohol in your system from an earlier drink at lunchtime?
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Hi, thanks for coming back to me, it is appreciated. I have researched the drinks I had, brand, size of drink, ABV % etc and I know through speaking with my girlfriend that I did not drink any more, I did not feel drunk and can remember what I drank also... So first two drinks finished at 19.30. Bac Calculator result from 19.30 - 00.30 with my drinks is 0.077 and 19.30 - 00.45 result is 0.073. The drinks I had are Krombacher in Weatherspoons. Two 500ml bottles at 4.8% between 19.13 and 19.30, drank quickly as I had a call and needed to leave. Then nothing until around 20:20 when I drank my first can of Fosters 440ml at 4.0% this was then at home. I continued to drink slowly another Two cans of Fosters 4.0% until 11.50pm. (three cans in total, I did open the 4th can and poured into a glass which was still there when I returned from the Police station at 4.30am). Is it possible that my breath test was higher than expected because I had only just taken a large swig of the Fosters and was highly concentrated in my breath but not my blood only 5 mins before being breath tested? Also by the time my blood was taken at 01:49 which the Police have now confirmed would the first two drinks I had be out of my system, this would be 6.5 hours later. Hope its not too confusing. Thanks again for your help!
 
Your problem is that your reading at 0030 (or 0045) has been shown to be 49 in breath, or 112 in blood. You say the BAC calculator says it should have been 77 or 73 in blood. That is why I say there was more alcohol in your system than you have remembered.
There would be no mouth alcohol to have affected the machine, I am not counting the roadside test, but going on the Police station one and I doubt that they would have allowed you to drink alcohol before blowing in there.
I still fear that you will come back over the limit at 84-89.
 
price1367 said:
Your problem is that your reading at 0030 (or 0045) has been shown to be 49 in breath, or 112 in blood. You say the BAC calculator says it should have been 77 or 73 in blood. That is why I say there was more alcohol in your system than you have remembered.
There would be no mouth alcohol to have affected the machine, I am not counting the roadside test, but going on the Police station one and I doubt that they would have allowed you to drink alcohol before blowing in there.
I still fear that you will come back over the limit at 84-89.
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Hi. I understand what you are explaining but I can assure that I only drank what I have said. I guess I will have to wait and see. Maybe i drank two drinks quickly or something towards the end but i definately drank what i have entered. Either way if the 2 drinks I had first between 19.13 and 19.35 (2 x 500ml @ 4.8%)had left my system at 01.49 then I only have to consider the three cans of Fosters between 08.40 and 11.30. Would this be correct? I am sorry for all the questions but I have alot riding on this, I will never put myself in this position again, thanks for your help!
 
The two cans would have disappeared by 0149, in fact they would have disappeared by 0045, but your reading of 49 then indicates 7 units of alcohol in your system, whereas you say that you drank 3 cans that add up to 5.25 units.
There is one other possibility, and that is that you had taken something that had an effect on your liver and you did not eliminate alcohol as normal. Even paracetamol can have an effect on your liver, but, whilst that is a reason for why a reading does not come down as would be expected, it does not constitute a defence to drink driving.
 
price1367 said:
The two cans would have disappeared by 0149, in fact they would have disappeared by 0045, but your reading of 49 then indicates 7 units of alcohol in your system, whereas you say that you drank 3 cans that add up to 5.25 units.
There is one other possibility, and that is that you had taken something that had an effect on your liver and you did not eliminate alcohol as normal. Even paracetamol can have an effect on your liver, but, whilst that is a reason for why a reading does not come down as would be expected, it does not constitute a defence to drink driving.
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Hi. That is a good point I had not thought off. I did take two Paracetamol around 20.00. So I guess that my body would have more alcohol in it than the calculator says due to a slower elimination time. That would be me stuffed then I think! Could the BAC still come under 0.08 if the blood was taken at 01.49 and last drink at 23.45? Both Police and solicitor have said it will be close. I feel completely fu**ed now! Clutching at straws. Devestated over this.
 
Hello there bud thought id chime in and give my two cents as I've been looking around the forum for weeks now since I was picked up 4 weeks ago for the same situation I'd had 3 pints of peroni a bottle of bud and 3 jäger bombs between 8pm to 12 was then picked up at roughly just after one in the morning had a breath test blew 54 at the roadside test and was literally devastated since I'd potentially lose my job and all the grief that goes with it, went back to the station took them an hour to get me back to the station since they were an armed response unit and couldn't take passengers in the back due to no room ect, anyway got off topic now I had my breath test at the station at 2:10 blew 44 twice within the 2 min intervals and then was given the option for bloods, took an hour and a half after my breath test for the bloods to be taken, now the part you're interested in I waited 4 weeks no letter and today I received a phone call from the officer who arrested me and gave me the good news that I was 72 on the blood test, hopefully this helps you and you come under.
 
JordC said:
Hello there bud thought id chime in and give my two cents as I've been looking around the forum for weeks now since I was picked up 4 weeks ago for the same situation I'd had 3 pints of peroni a bottle of bud and 3 jäger bombs between 8pm to 12 was then picked up at roughly just after one in the morning had a breath test blew 54 at the roadside test and was literally devastated since I'd potentially lose my job and all the grief that goes with it, went back to the station took them an hour to get me back to the station since they were an armed response unit and couldn't take passengers in the back due to no room ect, anyway got off topic now I had my breath test at the station at 2:10 blew 44 twice within the 2 min intervals and then was given the option for bloods, took an hour and a half after my breath test for the bloods to be taken, now the part you're interested in I waited 4 weeks no letter and today I received a phone call from the officer who arrested me and gave me the good news that I was 72 on the blood test, hopefully this helps you and you come under.
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Hi JordC. Thanks for yor reply. I am worried sick over this and could lose evrything I worked for, I only reversed my car about 30 yards! Anyway I think I would have come back as under the limit but I had taken Paracetamol which I forgot about. I now think this would slow down the rate my body got rid of the alcohol. This is why I think I will be over! Unless there is something I am missing. I am happy for you coming back under the limit, I hope I can post soon saying I was too but doubting that very much now. Not sure how long the Paracetamol would be in my system but I fear I am screwed! Thanks again.
 
All may not be lost if you come back over..... There can be special circumstances to not disqualify. One of them is that you only drove a very short distance so there was minimal risk to other road users. If you did only reverse 30 yards then that could well count. If that is all you did, how did you come to the notice of the Police? Very bad luck if they were just passing during those 20 seconds!
 
price1367 said:
All may not be lost if you come back over..... There can be special circumstances to not disqualify. One of them is that you only drove a very short distance so there was minimal risk to other road users. If you did only reverse 30 yards then that could well count. If that is all you did, how did you come to the notice of the Police? Very bad luck if they were just passing during those 20 seconds!
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Hi price. I did reverse my Car and it was bad luck but this is no excuse. I was barefoot and threatened by some dicks to move my car or they would 'smash me and it' I live with my two daughters and wanted to avoid confrontation. I am not condoning DD but this was real bad luck, and the thing is, it makes no difference to the court. Also because I have a good job I will not get legal aid and can not afford £1000s for solicitors. What can I do but deal with it! Devastated!
 
We can discuss your situation in some more detail if you come back over the limit, but for starters, did you tell the police that you were only reversing 30 yards and why you were moving it? Did they see you barefoot? Could they have come past because someone had seen you driving shortly before?
 
price1367 said:
We can discuss your situation in some more detail if you come back over the limit, but for starters, did you tell the police that you were only reversing 30 yards and why you were moving it? Did they see you barefoot? Could they have come past because someone had seen you driving shortly before?
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Hi. I did tell the Police that i was 'just moving it out of the way'. They did not see me drive forward only reversing. As I was reversing I noticed headlights in my mirror so moved to allow the car to pass. To my surprise and horror it was a Police car! The Police officer noticed I was barefoot and asked me why. I told him my shoes were in the house and I was only moving my car out of the way. It was very bad luck that they happened to turn into the street as I was reversing. Thanks for your reply, and your time, I am so worried over this. Cant really concentrate on anything else, it is always in my mind about what will happen and what I may lose!
 
You may have the basis of a not guilty plea, as the basic facts of what happened were made clear from the outset. As I said before, come back with the result, if it is over then I will see what can be put together, to do much more now could just be wasted effort....
 
price1367 said:
You may have the basis of a not guilty plea, as the basic facts of what happened were made clear from the outset. As I said before, come back with the result, if it is over then I will see what can be put together, to do much more now could just be wasted effort....
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Hi. I will wait for the result. It has been 3 weeks this coming Friday 12th so hopefully not to much longer. I just hope it comes back under. Thanks again!
 
Hi. So I have called today and been told I am being charged by post. Blood was 103. That's all I know right now.. How can I defend myself and put across the circumstances, I cant afford a solicitor if it's 1000s. I moved my car all of 50 yards, in reverse, with no shoes on. This was because I was threatened by lads to move the car. I will lose my job, maybe house and family over this. Feels very unfair, what can I do?
 
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