Units in a single gin and tonic (25ml, 37.5%)

Worked calculation

25 × 37.5 ÷ 1000 = 0.9

The tonic adds no units, so a single gin and tonic has the units of the 25ml of gin.

The NHS uses: units = millilitres × ABV (%) ÷ 1000. See the NHS guide to calculating alcohol units.

Compare with the weekly guideline

This drink is 0.9 units. The NHS low-risk guideline for regular drinking is not more than 14 units a week, spread over 3 or more days. The NHS calls this lower risk and does not call any amount “safe”. Read our guideline summary.

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FAQ

How many units are in a single gin and tonic (25ml, 37.5%)?

At 37.5% ABV and 25ml, there are about 0.9 UK units (25 × 37.5 ÷ 1000 = 0.9).

How is a UK alcohol unit calculated?

Units = volume in millilitres × ABV (%) ÷ 1000. This is the formula used by the NHS.

Is this a safe amount to drink?

This page only shows units, not safety. The NHS describes up to 14 units a week, spread over 3 or more days, as lower risk. The NHS does not call any amount of drinking safe. See our guideline page and NHS links for details.

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Not medical advice. Typical ABV varies by brand, so check the label or enter your own values in the calculator.