Drink Driving Limit- How Long After Drinking Can I Drive?

Know your drink driving limits:

NSW has blood alcohol concentration (BAC) limits: zero, under 0.05. The limit that applies to you depends on the category of your licence and the type of vehicle you are driving.

Your BAC measures the amount of alcohol you have in your system in grams of alcohol per 100 millilitres of blood. A BAC of 0.05 means you have 0.05 grams (50 milligrams) of alcohol in every 100 millilitres of blood.

'O' BAC applies to all:

• Learner drivers or riders
• Provisional 1 drivers or riders
• Provisional 2 drivers or riders
• Visiting drivers or riders holding an overseas or interstate learner, provisional or equivalent licence

Learner, P1 and P2 drivers and riders are developing their driving skills. They have a zero alcohol limit because they are more vulnerable to the effects of alcohol than experienced drivers. If you are on a zero alcohol limit, you must be alcohol-free while driving or riding. This doesn’t stop you from having fun, it just means you can’t drive or ride after drinking any alcohol.

If you have been drinking, Getting back to zero explains how long it can take to get alcohol out of your system. 

Check product labels for alcohol content

Some medicines, mouthwashes and food may contain alcohol. You should check labels for alcohol content (sometimes called ethanol). All products containing alcohol can affect your BAC.

If you are going to drive, avoid these products. Otherwise you may not be able to convince a court that you didn't have an alcoholic drink or another substance for the purpose of consuming alcohol.

Religious observance

If you have a BAC limit of zero and you are caught driving with a BAC above zero, but below 0.02, and you can prove to the court that you had the alcohol as part of a religious ceremony, this will be a defence.

Under 0.02 applies to:

• Drivers of vehicles of "gross vehicle mass" greater than 13.9 tonnes
• Drivers of vehicles carrying dangerous goods
• Drivers of public vehicles such as taxi or bus drivers

A BAC of 0.02 can be reached after the consumption of only one standard drink (a middy of beer, a nip of spirits or a small glass of wine). Drivers subject to a 0.02 limit should not drink any alcohol before driving.

Under 0.05 applies to:

• ALL other licences (including overseas and interstate licence holders) not subject to a 0.02 or zero limit
• Under 0.05 is the legal limit for most drivers

Don’t risk trying to calculate your BAC

Trying to calculate your BAC is impossible. Your BAC begins to rise as soon as you start drinking and can continue to increase for up to two hours after you have stopped drinking. Counting standard drinks to guess your BAC is difficult and often inaccurate because:

• Alcohol concentrations vary between drinks, such as light beer (2.5%), full strength beer (5%), wine (14%) and spirits (40% or higher)
• Beer may be served in schooners, middies and schmiddies. Wine glasses vary in size from 100ml to 280ml or more
• Drinks are often ‘topped up’ so its impossible to know how many standard drinks you’ve had
• Drinks come in non-standard sizes – many pre-mixed drinks sold in bottles or cans may contain more than one standard drink and 800ml bottles may contain three standard drinks

People are different

Alcohol also affects people differently. Two people who drink the same amount can have different BACs. This is caused by factors such as:

• Size and weight – a smaller person will have a higher BAC from the same amount of alcohol
• Gender – a woman the same height and weight as a man, drinking the same amount, will have a higher BAC
• Liver function – an unhealthy liver will process alcohol slower than a healthy liver
• Recent consumption of food – lack of food in your stomach means you will absorb alcohol into your blood faster. However, eating food after you have been drinking will not reduce your BAC
• Fitness, fatigue and general health condition – your BAC can be higher if you are not feeling well, you are tired, stressed or unfit

We recommend that you don’t drink any alcohol if you plan to drive. Alcohol affects different people in different ways and attempting to guess your blood alcohol concentration is difficult and inaccurate.

What Defines Drink Driving?

There are two types of drink-driving offences.

One is exceeding the Prescribed Concentration of Alcohol (PCA), and the other is Driving Under the Influence (DUI). 

Exceeding the PCA is the most common form, and these cases are usually identified during routine police breath testing. 

DUI describes the impaired ability to control a vehicle.

What Does BAC Stand For? 

This calculator is based on the Australian standard for Blood Alcohol Content or BAC calculators, which is AS 4308.1:2015. The calculator is accurate to within 0.01% BAC.

To use the calculator, you will need to enter your weight, gender, and how many drinks you have had. The calculator will then display your estimated BAC.

It is important to note that this calculator is only an estimate. Your actual BAC may be higher or lower than the estimate provided by the calculator. If you are concerned about your BAC, it is best to get a professional test.

Here are some of the factors that can affect your BAC in Australia:

• Your weight: The heavier you are, the slower your body will metabolize alcohol. This means that you will have a lower BAC than someone who is lighter.
• Your gender: Men tend to have a higher BAC than women after drinking the same amount of alcohol. This is because men have more body water than women, and alcohol is more easily absorbed into body water.
• Your metabolism: Your metabolism is the rate at which your body converts food into energy. People with a faster metabolism tend to have a lower BAC than people with a slower metabolism.
• Your food intake: Eating food before or while you are drinking can slow down the absorption of alcohol into your bloodstream. This can help to lower your BAC.
• Your medical conditions: Some medical conditions, such as liver disease, can affect the way your body metabolizes alcohol. This can lead to a higher BAC.

The legal limit for BAC when driving in Australia is 0.05%. If you are caught driving with a BAC of 0.05% or higher, you will be charged with drink driving. The penalties for drink driving can be severe, including fines, imprisonment, and the loss of your drivers license.

If you are planning on drinking alcohol, it is important to plan ahead. Make sure you have a designated driver who will not be drinking, and make sure you have a safe place to stay where you can sober up before driving.

What is the Legal Drink Driving Limit?

For full licence holders, the maximum BAC is 0.05%.

For learners, provisional and probationary licence holders, taxi and bus drivers, and drivers operating vehicles over 15 tonnes, any measure of alcohol in the blood is a breach of licence conditions. Your BAC must be 0.00%. 

When Can I Drive After Drinking?

So, now comes the question most of us have asked ourselves at some point: how long after drinking can I drive in Australia?

Unfortunately, there’s no straight answer. There are a number of different factors that determine your BAC and how quickly you metabolise alcohol, including

• Your sex
• Your weight
• Your age
• What type of drinks you consumed
• What you’ve eaten
• How much you’ve eaten
• Supplements or medications youre taking
• Fitness levels

For this reason, there is no prescribed ‘wait time’ between drinking and driving that guarantees a safe BAC level. Small amounts of alcohol leave the body in urine, breath, and sweat. A healthy liver will break down less than one standard drink per hour, but if your liver is damaged, this can take longer. Have you ever heard that coffee, showers, water, and food can help sober you up? While they may make you feel better, these remedies will not change your BAC levels. Time is the only thing that can do that. After a heavy night of drinking, it can take over 18 hours for your BAC to fall back to zero. In fact, many people are charged with drink driving offences the day after a night out. 

How Long After Drinking Can I Drive on P Plates?

If you’ve recently graduated from a learner’s licence to a probationary licence, you’ll be relishing the freedom of driving without a supervisor or instructor.

However, there are still a number of rules and restrictions you must abide by when holding a probationary licence. A probationary licence does not come with the same BAC permissions as a full licence. Your BAC must be 0.00% when holding a learner’s or probationary licence.

That means you may not, under any circumstances, consume an alcoholic beverage and then drive. 

How Many Drinks Can You Have and Drive?

The number of drinks you can have before driving will differ from person to person, depending on the various factors mentioned earlier. Unfortunately, there’s no one answer to this question. 

The only way you can be sure you won’t be driving above the 0.05% limit is not to drive after drinking. 

How Many Drinks is 0.05? 

Many people operate under the generalised rule that 2 standard drinks in the first hour will raise your BAC to 0.05%.

This rule of thumb also states that a standard drink for each subsequent hour will maintain your BAC at 0.05%. Any more than that, and your BAC will rise above the 0.05% legal limit. 

However, it’s important to remember that this rule is oversimplified. 

As mentioned, various factors determine the way your body absorbs and responds to alcohol. 

Additionally, alcohol concentrations vary between drinks. For example, 40% proof Vodka will increase your BAC faster than a 4% beer. Serving sizes also act as another variable, and pre-mixed drinks complicate things further.  

Consider this; how can you calculate the number of standard drinks you consumed from a shared bottle of wine? What about the drink you took just a few sips of? Do you know how much vodka was in the drink your friend mixed for you?

Counting drinks is not a safe or reliable way to determine whether or not you can drive. 

How Long Does Alcohol Stay in the Blood?

Generally, it takes the body around an hour to process one standard drink. 

However, two people can consume the same amount of alcohol and produce different BACs due to the aforementioned factors that influence how alcohol is absorbed into the body.  

Blood Alcohol Calculator

There is a range of BAC calculators online that can be used to give you a rough estimate of your BAC levels. Keep in mind that these calculators only provide estimates and cannot guarantee 100% accuracy. Under no circumstances should these calculators be used to determine whether or not you should get behind the wheel. You can also purchase breathalysers from a variety of online websites and car accessory stores. If the price for the device seems too good to be true, it probably is; the technology in cheaper versions is likely dated and inaccurate. If you’re going to purchase a breathalyser to get an idea of your BAC levels, opt for a device from a reputable brand. Even still, the results from these devices will not be as accurate as the results from the official police BAC reader. A calibrated testing machine is the only way to measure your BAC accurately. 

The only way to ensure you are under the legal limit is to follow this simple rule: if you are going to drink, do not drive. 

For the safety of yourself and other road users, if in doubt, sleep it out. 

What’s the Penalty for Drink Driving?

Laws and penalties vary from state to state.

If convicted of an offence, the court will revoke your licence for a certain amount of time, depending on; your level of intoxication, other offences, and if you’ve had a prior history of drink-driving. Once their licence has been returned, anyone who has committed a drink-driving offence must install an alcohol interlock into their vehicle for a set period. 

Fully-licenced drivers who measure a BAC of between 0.05 to 0.07% will receive a fine and incur 10 demerit points. For drivers who record a BAC over 0.07%, the licence will be cancelled, and they will need to install an interlock for at least six months when relicensed. 

Repeat drink drivers will have their licence cancelled and are required to install an interlock.

Learner and probationary drivers who have a BAC below 0.05% will have their licence cancelled for three months. They will also need to install an interlock for at least six months when they are licensed. Remember, the consequences of losing your licence are significant. For many people who require a car for work, this can result in a loss of employment. 

In some cases, a drink-driving offence can lead to prison time. As of 2011, it is also an offence to drink alcohol while sitting next to a learner driver, even if there is no alcohol in the driver’s breath or blood. 

Why would anyone risk their life

Drink driving limit is applies when you drink. The sole guarantee of staying below the Australian drink driving limit is refraining from driving after consuming any alcohol whatsoever. Determining a precise timeframe for safe driving after drinking is complex, hence it's wisest to err on the side of caution.

If you intend to consume alcohol, it's advisable to designate a sober driver or opt for alternative transportation like Uber or taxi services.

No social outing is worth jeopardizing lives.

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