Free Alcohol Units Calculator — Count UK Units Across a Whole Session

“I only had a few.” Most of us have said it — and most of us are wrong about what “a few” actually adds up to. The label on a bottle tells you the ABV, but the number that matters for your health is units, and units depend on volume as much as strength.

The new Alcohol Units Calculator turns a real drinking session into two honest numbers: total UK units and total grams of pure ethanol.

Why a single-drink calculator isn’t enough

A pint of strong lager (5.2% × 568 ml) is nearly 3 units. A small glass of wine (12% × 125 ml) is about 1.5. People consistently underestimate the strong pint and overestimate the small wine — so a tool that only does one drink at a time misses the point. Real evenings are a pint and a glass of wine and a shot.

This calculator is built for sessions. Pick a preset (ABV and volume auto-fill), set how many you had, then add another row for the next drink. The total updates live, and a five-band progress bar shows your session against the 14-units-per-week low-risk guideline from the UK Chief Medical Officers.

What you get

• Eight UK drink presets — pints, wine glasses, single and double spirits, alcopops — plus fully custom ABV and volume
• Multi-drink rows that total automatically
• Grams of ethanol alongside units (1 unit = 8 g), so you can see what your liver actually has to process
• A weekly-limit bar with five risk bands, from “small share of the week” to “exceeds the whole week’s guidance”

If you want the maths behind the numbers, read UK Alcohol Units, Explained — it walks through where the 14-unit figure comes from and why a pint isn’t the “2 units” people assume.

What it deliberately does not do

This is an informational tool, not medical advice, and not a sobriety test. Units measure how much alcohol you drank — not how drunk you are. Blood alcohol concentration depends on your weight, sex, food, and time, none of which this tool asks for. Never use it to decide whether to drive.

It also stores nothing. Every visit starts fresh, the maths runs entirely in your browser, and no drink entry is ever sent anywhere. For people who want to track moderation over months, a future Pro tier would add an optional private history with trend charts and a GP-ready export — but the core calculator on the tool page stays free forever.

Frequently Asked Questions

What is a UK unit of alcohol? One UK unit is 10 ml (8 g) of pure ethanol. The formula is units = (ABV% × volume in ml) / 1000, so a 568 ml pint of 4% lager is 2.27 units.

Where does the 14-units-per-week figure come from? It is the UK Chief Medical Officers’ 2016 low-risk drinking guideline, applied equally to men and women, with a recommendation to spread drinks over 3+ days.

Does it tell me if I’m safe to drive? No. Driving safety depends on blood alcohol concentration (BAC), not units. Use a dedicated BAC calculator and never drive after drinking.

If you or someone you know is struggling with alcohol, this tool is no substitute for professional support — speak with your GP or a qualified service.

Try it now — Open the Alcohol Units Calculator — no signup required.