There’s no fixed benchmark of how much you can drink before driving. Different drinks contain different level of alcohol content. Other factors include your body size, age, gender, and how much you are able to tolerate alcohol.

Alcohol will impair your driving judgment, coordination and reactions. The more you drink, the slower your reaction will be to the road condition. Your ability to proper control of the vehicle will also be affected.

When the alcohol enriched blood passes through the lungs, some of the alcohol will be circulated into the air in the lungs which can be detected by a breath sample taken by the breathalyser.

According to the Traffic Police of Singapore, and under the Road Traffic Act, a driver can be found to be convicted of drink driving in the following two instances, even if he has control of the vehicle.

Here are some key points about drink driving rules in Singapore as of my last update:
Blood Alcohol Concentration (BAC) Limit: Singapore has a very low legal BAC limit of 0.08 grams per deciliter (g/dL) of blood. This is lower than the limits in many other countries.

Penalties: Penalties for drink driving in Singapore are severe. They can include fines, imprisonment, and even caning in some cases. The severity of the punishment depends on various factors, including the level of intoxication and whether it is a repeat offense.

Penalties for First-Time Offenders will be a fine between SGD 2,000 and not more than SGD 10,000 with up to 12 months in jail. A suspension of the offender’s driving license for a minimum of 12 months.
A second-time offender or a successive offender will face a compulsory jail term of up to two years in addition to a fine amounting to between $5,000 to $20,000. The offender will also be banned from driving for a minimum of five years.

Random Breath Tests: Singapore’s traffic police regularly conduct random breath tests at checkpoints, especially during the festive seasons and holidays. If you’re pulled over and fail a breath test, you can be arrested immediately.

Roadblocks: The police set up roadblocks and conduct spot checks for drink driving. They may also perform field sobriety tests if they suspect a driver is under the influence.

Zero Tolerance for Young and New Drivers: Singapore has a zero-tolerance policy for young and novice drivers. This means that drivers holding a provisional driving license or those under the age of 21 are not allowed to consume any alcohol before driving.

Penalties for Passengers: Passengers can also be penalized if they knowingly allow someone who is intoxicated to drive.

Insurance: If you are involved in an accident while driving under the influence, your insurance coverage may be invalidated, and you may be personally liable for damages and medical expenses.

Alternative Transportation: Singapore has a well-developed public transportation system, including taxis and ride-sharing services like Grab. It is highly advisable to use these alternatives if you’ve consumed alcohol.

Designated Drivers: If you plan to drink, designate a sober driver or use a taxi or ride-sharing service to get home safely.