How Many Calories in a Gin and Tonic

A classic gin and tonic made with a single 25ml measure of gin and 150ml of regular tonic water contains approximately 120 to 130 calories. The exact amount can vary slightly depending on the brand of gin and the type of tonic used. Gin itself is relatively low in calories, around 55 to 60 calories per 25ml shot — but tonic water adds a significant sugar and calorie load, often around 70 calories per glass.

For those who prefer a double measure (50ml), the calorie count increases accordingly, bringing the total closer to 180 to 200 calories per drink, depending on the tonic.

The Type of Tonic Matters

The biggest factor influencing the calorie content of a gin and tonic is the type of tonic water used. Traditional tonic contains added sugars that make it considerably more calorie-dense than the spirit itself. However, using a diet or slimline tonic can cut the calorie content dramatically. With a single measure of gin and a calorie-free tonic, the drink drops to around 55 to 60 calories total.

This swap doesn’t significantly alter the flavour for most people, and it’s one of the simplest ways to enjoy a gin and tonic without the extra calories.

What Else Affects the Calorie Count?

Some gin brands are flavoured or infused with botanicals, citrus, or sweetened extracts, which can increase their calorie count slightly. Garnishes like lime or cucumber add negligible calories, but using syrups, sweet liqueurs, or fruit cordials can add up fast. A gin and tonic mixed with elderflower tonic or flavoured mixers, for example, may contain 150–180 calories or more per glass.

Additionally, larger servings such as those commonly poured at home or in bars (often 35ml or 50ml) raise the calorie total significantly compared to a single 25ml shot.

Nutritional Breakdown

A standard gin and tonic contains almost no carbohydrates, fat, or protein from the gin itself. All of the carbohydrate and sugar content comes from the tonic. Regular tonic water contains around 15 to 18 grams of sugar per 150ml, which is roughly 3 to 4 teaspoons. Diet or slimline tonic typically contains artificial or non-nutritive sweeteners instead of sugar, reducing both calorie and glycaemic impact.

How Gin and Tonic Affects Your Diet

While not the most calorie-heavy alcoholic drink, gin and tonic can still contribute to hidden calorie intake, particularly when consumed in multiples. Two or three gin and tonics in an evening can easily exceed 300–400 calories, often without providing any sense of fullness. For those watching their weight or counting calories, it’s wise to be mindful of portion size and mixer choice.

On the positive side, gin and tonic is gluten-free, relatively low in carbohydrates if made with diet tonic, and easy to portion compared to sugary cocktails. It’s also a lower-calorie alternative to wine, beer, or creamy liqueurs, especially when modified sensibly.

Alcohol Itself Adds More Than You Might Think

While gin has no carbs or sugar, alcohol itself is calorically dense, delivering around 7 calories per gram, almost as much as fat. That means even pure spirits like gin still carry a calorie load. A single 25ml shot has about 55–60 calories, and a double (50ml) adds up to 110–120 before you’ve even touched the tonic.

The real calorie trap is assuming gin is “low-cal” just because it looks light and clear. In reality, multiple measures quickly stack up the energy intake, particularly when paired with sweet mixers.

It's a Low-Satiety Source of Calories

Like most alcoholic drinks, gin and tonic provides empty calories meaning it gives you energy, but no nutritional value. It won’t fill you up, and in fact, alcohol can stimulate appetite, leading to overeating during or after drinking. This is part of why drinking calories is more dangerous for weight gain than calories from solid food.

A couple of gin and tonics paired with snacks or a takeaway can unintentionally add 500–1,000 calories to a night out.

Sugar-Free Tonics Still Have an Effect

Diet tonics dramatically cut the calorie count, but it’s worth noting that sweeteners like aspartame, acesulfame-K, or sucralose can still affect people differently. Some individuals find that artificial sweeteners increase cravings for sweet foods, even though they don’t contribute calories. While they’re a smart swap in moderation, they’re not a magic fix if they trigger additional snacking.

The Bigger the Glass, the Bigger the Problem

Gin is often served in oversized balloon glasses, especially at bars and restaurants. These often hold 250ml or more of tonic, which can bring the calorie count to 150+ per drink if a full-sugar tonic is used. Double measures of gin are also common in these settings, making it easy to sip down 200 calories or more in one “glass” that doesn’t feel oversized.

Being aware of measure sizes and mixer volumes is just as important as knowing what's in the drink itself.

Comparing to Other Alcoholic Drinks

A small glass of white wine (125ml) has around 85–90 calories, a pint of lager contains about 180–220 calories, a vodka and soda with lime has 55–60 calories, making it one of the leanest alcoholic drinks available.

This comparison helps reinforce why a diet gin and tonic is one of the better alcoholic choices for calorie-conscious individuals but only if portioned sensibly.

Summary

A typical gin and tonic made with a single shot of gin and regular tonic water contains 120 to 130 calories, most of which come from the tonic. Switching to a diet tonic can reduce the calorie content to just 60 calories per drink. While it’s not excessive, repeated servings or sweetened variations can turn this light cocktail into a high-calorie habit. Choosing smaller measures and sugar-free mixers is an easy way to keep things in check while still enjoying this classic drink.