A drink carries four figures

Units / standard drinks = the health line

Official low-risk figures are written in a local measure of pure alcohol, not in glasses. The UK Chief Medical Officers advise no more than 14 units a week, spread over three or more days. A UK unit is 8 g, or 10 ml, of pure alcohol. France uses a 10 g verre standard and a weekly cap of 10. The US uses a 14 g standard drink and publishes daily limits. The guidelines page has the sources. This page does not repeat those tables.

The UK formula is millilitres times ABV, divided by 1,000. A 568 ml pint at 4.5% is 2.6 units. A 175 ml glass of 13% wine is 2.3. A 250 ml glass of the same wine is 3.3. Strength and pour size move the number more than the word on the menu.

That number is the one that sits next to a published weekly line. It is also the one that does not care whether the pour was "just a glass." If you want the health comparison, this is the figure to log. Risk still rises before 14. The line is a ceiling, not a ration.

Calories

Alcohol itself carries about 7.1 kcal per gram. That is chemistry, not a drinking guideline. Nobody's official weekly figure is written in calories. A 175 ml glass of 13% wine holds about 18 g of pure alcohol, so roughly 127 kcal from the alcohol alone. Residual sugar adds more. A pint of beer or cider adds carbohydrate on top of the alcohol calories, so the real pint is higher than the alcohol-only figure.

Calories are useful if that is already how you look at food, or if the week's drinking is showing up on a label you already watch. They are a poor substitute for units. A vodka soda can be modest in calories and still be several units. A pint can look heavy in calories partly because of the malt, not only the alcohol. Mixing the two jobs is how a "light" week stays heavy in units.

The calculator shows the alcohol calories for any pour. It does not add mixer sugar or beer carbs. Treat the calorie column as a floor, not a receipt from the kitchen.

Spend (often the figure that moves first)

Money is the number most people already understand. A week of £40 in pubs is easier to feel than 18 units, and it shows up on a bank statement without a formula. For a lot of people, spend is the first figure that makes a cut-back plan real, because it is the one they were already looking at.

Log what left your pocket, in the currency you actually paid. A £6.50 pint is £6.50 whether it was 2.2 units or 3.2. That is the point: spend tracks the bill, not the alcohol. A round of four pints is four pints of spend if you bought it, even if you drank one. A bottle opened at home is the shelf price, spread however you choose, as long as you do it the same way every time.

Spend will not tell you where you sit against 14 units. A cheap, strong cider week can look modest on the statement and heavy on the health line. An expensive cocktail week can look alarming in pounds and sit under the guideline. Use spend when the job is the bill. Switch to units when the job is the line.

A worked month helps. Four Friday pints at £6.40 is £25.60 and about 10.4 units if they are 4.5%. Add two large wines at £8 and 3.3 units each, and the month's "quiet" Fridays are already more than a UK week of units and more than £40 before any Saturday. The statement shows the money in one line. The unit total only shows up if you logged the pours. That is why spend often moves first: the bank already did the adding.

Why counting only "drinks" lies

"Drinks" collapses four different things into one tick. The pour volume, the strength, the energy, and the price. A single 25 ml spirit at 40% is 1 UK unit and maybe £2.50 at home. A 250 ml wine at 13% is 3.3 units and £8 in a pub. Both get written down as one drink. Three of the second is already 10 units and most of a UK week, and the notebook still says three.

Pub "glasses" make it worse. A small wine is often 125 ml, a standard 175, a large 250. Three larges of 13% wine are about 10 units before the rest of the week starts. Home pours drift the other way: the glass is whatever left the bottle. If the log uses the menu word, you are counting the menu, not the pour.

Doubles hide in the same trick. A "gin and tonic" at a bar is often 50 ml of 40% spirit, which is 2 UK units, plus mixer calories the alcohol-only column will miss. Two of those and a pint is already a UK "low risk" day on its own, written down as three drinks. The word "drink" is doing four jobs at once.

How to pick one number to watch this month

One number you will actually look at beats three you ignore. For four weeks, pick the job, then pick the unit that matches it.

• The job is the official line. Count UK units, French verres, or US standard drinks, matching the guideline you are reading. Sit the week next to that figure. The cut-back page is about that job.
• The job is the bank statement. Count spend. Keep a rule for rounds and for bottles at home. Do not convert it back into drinks at the end of the month.
• The job is energy, because that is already how you eat. Count alcohol calories, knowing they are a floor. Do not treat a low-calorie pour as a low-unit pour.

After a month you will know which figure surprised you. That is the one to keep. Adding the other two later is cheap. Starting with all three is how the log becomes a chore.

If you already know the job is the health line, skip the other two for now and use the calculator once for the pours you actually buy, then log those. Recalculating every glass from first principles is how people stop logging by Wednesday.

How Modraly uses these figures

Modraly logs units, spend and calories on the iPhone and sits the week next to the official figure for your country. It does not rank the three or tell you which to care about. For a programme or a coach, start with the comparison.

Modraly is not a medical device and does not provide medical advice. The NHS and Alcool Info Service are the right starting points for personal health questions.