The health ministry has created an online tool that calculates how long it takes alcohol to break down in the body to encourage people to make more informed decisions when drinking.

The “Alcohol Watch” website allows people to enter various types of drinks, such as beer, chūhai or sake, along with the amount they consumed to calculate the total pure alcohol content and the time required for it to break down.

For example, if the user selects a 500 milliliter can of beer with 5% alcohol, a 120 ml glass of wine with 12% alcohol and a 30 ml glass of whiskey with 40% alcohol, the estimated breakdown time provided by the tool is 10 hours and 17 minutes from when the person stops drinking. It would be best to avoid driving for that period of time, the website advises.

The tool works based on research data compiled by a variety of alcohol-related academic societies.

However, women generally have less body water than men, meaning the amount of alcohol that can be metabolized is also lower in women compared to men. Women are also more likely to be affected by alcohol due to estrogen and other factors. As a result, they may experience greater alcohol-related health risks, even with smaller amounts of alcohol, according to ministry guidelines on responsible drinking released in February.

Alcohol Watch takes these factors into account and provides a breakdown estimate that will be long enough for most people, according to a ministry spokesperson for the addiction prevention and support office.

“The idea of quantifying lifestyle habits is essential because by making them visible, you’re able to possibly prevent issues,” said the spokesperson.

In the February guidelines, the ministry warned that drinking large amounts of alcohol quickly can cause acute alcohol poisoning, with symptoms such as reduced consciousness, vomiting and breathing difficulties. Long-term heavy drinking also raises the risk of alcohol dependence, lifestyle diseases, liver disorders and cancer.