Standard Drink Calculator
When drinking the standard drink calculator enables you to determine the standard drink
value for the drinks you are having. You need to know the size/volume of the drink
and the per cent alcohol by volume. These values are easily found on the container. If
you're pouring from a larger container to a smaller container such as pouring from a bottle
to a glass, you need to know the smaller container size/volume.
When being served alcohol in a restaurant it may not be easy to determine the alcohol content
or the volume of the glass. In that case it may be necessary to ask the wait staff.
The volume of the container such as can, bottle, or glass.
The alcohol content is shown on the container as the percentage alcohol by volume.
Whilst the Standard Drink Calculator has been primarily designed to help people determine
the number of standard drinks in a single drink, when drinking people often drink the same
drink a number of times over the course of time. Number is used to enter the number of drinks
of the same size and type to determine the number of standard drinks consumed.
By default the Standard Drink Calculator is set for usage in Australia. Different countries
define a standard drink with different amounts of alcohol. A standard drink as defined in the UK
contains less alcohol than a standard drink in Australia, which in turn has less alcohol than
a standard drink in the USA.
The number of standard drinks based on the size/volume, per cent alcohol by volume, for the
number of drinks, for the nominated country.
Ave Hours to Zero
This number is the average number of hours for the liver to metabolise the alcohol. The figures
to the right are the average taking into account the minimum and maximum time the liver
metabolises alcohol. A damaged liver for example could take the maximum time.
Ave Hours to 0.05
This number is the average number of hours to reach 0.05 taking into account the litres of blood
blood an average person has. The figures to the right show the minimum and maximum based on
the range of litres of blood for adult humans. It should be noted this figure does not take
into account the metabolising time of the liver but uses the average figure for the liver.
Spirit measures for a single spirit drink are 15ml, 30ml and 60ml. The measures are not defined
if the spirit is mixed such as in a cocktail.
There is no prescribed sizes for beer, stout or ale. But there are common sizes of glass names,
however the names may differ across Australia.
On average the body metabolises 7.5 grams of alcohol, however this can vary from 4 - 12 grams.
The human adult body contains from 4.5 to 5.5 litres of blood. Five litres has been used as the average.
Another fiture often mentioned is the amount of blood is estimated at 7% of the body weight.
As you can see the rate at which the liver can metabolise alcohol can have a large impact on the time
for the body to remove the alcohol. In addition the volume of blood the body contains also affects
the blood alcohol content. A slow processing liver with a person with a smaller frame could result
in a person having a much higher blood alcohol content at a point in time than expected.
The location where someone lives also affects the amount of blood their body has. A person
living at a higher altitude will have a larger amount of blood due to their oxygen requirements.
When does the time start? That depends. If you're a consistent drinker over the night the
time starts when you start drinking. Keep in mind it takes approximately 20 minutes for your body
to start processing the alcohol, so it can take a while for your BAC to peak. If you down
quite a few shots at the end of the night, then it's probably best to start from then.
Keep in mind the calculator is just an estimate.
A simple guide to drinking is allow an hour for each standard drink and then add an additional hour
to stay under 0.05.
Some drinking containers can help you, but others can mislead you. Bottles and cans let
you know immediately the volumen and alcohol content. At restaurants glass sizes vary
so you may find it hard to estimate. At home there's such a variety of glass sizes
you should probably find glasses that help you. E.g. Know the size by measuring the volume.
Perhaps there's marks on the glass to help when pouring mixed drinks, if not then
perhaps use a standard measure.
If being zero is vital (due to employment or driving restrictions), it's best to be very conservative
and use the maximum time to zero, or even longer. Best to be error on the side of caution
than take any chances.
The Standard Drink Calculator is based on the time it takes for the body to metabolise alcohol.
However this time can be greatly increased if there is food intake as food digestion slows
the rate at which alcohol is absorbed. This could mean it can take longer to reach the peak,
and importantly for those who need to be at zero BAC, the time it takes to return to zero.
This section contains links to articles I feel may interest others. The articles
linked to will generally be from scientific studies, educatin, or government sites, as these are felt to contain
better researched information.
Absorption and Peak Blood Alcohol Concentration After Drinking Beer, Wine, or Spirits
The article indicates in a fasting state, absorption of alcohol occurs faster with a greater BAC peak
for spirits, then wine, then beer.
The variation bars on the graph shown in figure 1, shows
the considerable variation between people.
After two hours the variation no longer appears significant.
To read the graph the vertical access has a unit of measure of mg/dL, which means
50 mg/dL is the same as 0.05 g/100ml, the measurement used in Australia for 0.05.
The drink was consumed in two 10 minute intervals with half the drink consumed in each interval.
The measuring of blood alcohol content would have then started at 20 minutes. It appears from the
graph which starts at 20 minutes, it doesn't appear alcohol at this point had reach the blood.
Notice the peaks for spirit, wine and beer respectively appear after 36, 54, 62 minutes plus or minus a
The amount of alcohol consumed was 0.5 g (ethanol) per kg of body weight. The mean weight was 82.66 kg.
This means the volume of alcohol varied based on a person's weight. Thus we can't say people had so
many standard drinks. Using the mean we can say the average number of standard drinks was 4.133
(0.5 g ethanol x 82.66 mean kg weight / 10 g for stand drink in Australia).
From the Glass to the Brain in Six Minutes
An interesting article which indicates alcohol starts to have an effect on the brain within six minutes. The
original paper can be found here.
National Institute on Alcohol Abuse and Alcoholism No. 35; PH 371 January 1997
I've included this article as it contains a graph showing the BAC over time, for eight
fasting males, for one, two, three and four. The amount of alcohol in a drink was 11.2 grams.
Notice how the graphs aren't quite linear as the BAC reduces. That means we need to realise
the rate of removal of alcohol from the body slows down towards the end. This is important
for those who need to have zero BAC.
The slope indicates a reduction of approximately 6.5 g of alcohol per hour. This is less than
the calculator which is based on 7.5 g per hour.
An important point for this study is the amount of alcohol is the same for all people irrespective
of their size/weight. Larger people have more blood which generally means a lower BAC,
although this is not always the case.
In this study the zero time is before the alcohol has been consumed. The first measurement
for 1 and two drinks was at four minutes and a BAC was detected.
From the graph you can see the BAC increases shortly after the zero time point, indicating
the alcohol starts being absorbed into the blood quite quickly.
For each additional drink the peak is being reached later.
is for the actual paper the graph is based on.
The Standard Drink Calculator web app comes with no warranty expressed or implied.
The Standard Drink Calculator web app is only for informational purposes and is not guaranteed to be error free.
The information on this page is not intended to be advice.