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How Much Caffeine Is In Diet Coke? 2024 Breakdown

hand holding a can of diet coke

Caffeine (serving: 12 fl oz)
46 mg
Caffeine (mg / fl oz)
Caffeine strength

Many of us need to watch the caffeine levels in our food and beverages to stay healthy and sleep at night. Diet soda is also popular because of its low calories and sugar content, so people wonder how much caffeine a diet soda like Diet Cole contains. The short answer is that a 12-ounce Diet Coke contains 46 milligrams of caffeine. However, there is more to consider, like what’s the limit and how much is too much?  If you need to watch the caffeine levels in your diet, keep reading while we look at the caffeine in Diet Coke and how it compares to other brands to help you be better informed.

The Short Answer
There are 46 milligrams of caffeine in a 12-ounce can of Diet Coke and 70 milligrams in a 20-ounce bottle. This is a little bit more than regular Coke and about half as much caffeine as a cup of coffee.

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What is Caffeine?

Caffeine is a naturally occurring stimulant that affects the central nervous system, helping the user overcome fatigue. It has a long history, and most experts consider it safe though it can be harmful to your health in large doses. Caffeine can also lead to hyperactivity with symptoms similar to sugar when used by children. Most people know about it from its presence in coffee and tea, but it is also present in soft drinks like Diet Coke and in energy drinks like Red Bull.  There is also caffeine present in foods, like chocolate and energy bars.

How Much Caffeine In Diet Coke?

According to Coca-Cola, you can expect there to be 46 milligrams of caffeine in one 12-ounce can and 70 milligrams in a 20-ounce bottle. The caffeine level in Diet Coke is slightly higher than it is in regular Coke, which typically has about 32 milligrams in a 12-ounce can and 50 milligrams in a 20-ounce bottle.

The caffeine added to Diet Coke and other drinks is often synthetic. While being almost identical to the naturally occurring caffeine in coffee, the synthetic version is much cheaper to produce. By being made in a lab, this version of caffeine can be added to soft drinks, sports drinks, and even foods to help improve the taste. Considering sodas are made from kola nuts, which have naturally occurring caffeine, the addition of synthetic caffeine improves taste and is why Diet Coke has a higher caffeine content than regular Coke. Most diet soft drinks use these additions to improve taste for those reducing their caloric intake.

a can of diet coke at the beach
Image Credit: Corrie Miracle, Pixabay

How Does the Caffeine in Diet Coke Compare to Other Beverages?

Coffee: 109 milligrams
Tea: 75 milligrams
Energy Drinks: 160 milligrams

While the caffeine in Diet Coke is quite high compared to regular Coke, both are low compared to other beverages. The standard cup of coffee typically has about 109 milligrams of caffeine, but plenty of brands contain more. Starbucks Dark Roast coffee contains 260 milligrams of caffeine per 12-ounce serving.  Energy drinks can also contain a considerable amount of caffeine, with many 12-ounce cans containing 160 milligrams or more. The tiny 2-ounce Five-Hour Energy Drinks contain 200 milligrams in each bottle. Compared to these foods and beverages, Diet Coke has relatively little caffeine.

Is Diet Coke a Healthier Option?

When it comes to Diet Coke as a healthier alternative, caffeine isn’t the real issue. The reason most people switch to Diet Coke is to rid themselves of the excess sugar in regular soda. As we all know, sodas have a high sugar content and can be extremely dangerous when consumed excessively. For those hoping to avoid issues with their weight and the medical conditions that go hand-in-hand, Diet Coke may feel like the answer. Unfortunately, this is the only benefit you may find.

The Downside of Diet Sodas

Like with most things in life, there are downsides to drinking Diet Coke and other sodas like it. These types of drinks have been linked to several medical conditions but with it so difficult to fully control proper studies, it’s still considered theories. Heart disease, liver issues, and obesity are common factors of those who drink a lot of diet soda, but other factors such as medical and family history also come into play. It is always best to speak with your doctor and keep them in the loop on any big changes you make in your diet. This includes adding Diet Coke in hopes of losing weight or reducing sugar intake.

How Much Caffeine Is Too Much?

Most experts agree that drinking up to 400 milligrams of coffee each day shouldn’t cause any serious health problems, but everyone has a different tolerance based on their age, health, weight, and other factors. However, they are quick to point out that it is easy to consume more caffeine than you expect when drinking coffee or tea because the actual amount of caffeine can vary. Luckily Diet Coke provides you with a consistent and predictable amount, so it’s easy to tell when you’ve had too much (about eight cans), and the amount is low enough that you shouldn’t need to worry about it.

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At 46 milligrams per 12-ounce serving, a can of Diet Coke should provide you with enough energy to get you moving in the morning without risking health problems. You can drink more than eight cans in a single day before exceeding the recommended limits, which is more than most people are likely to drink, and since the amount is consistent, you are less likely to consume too much accidentally.

We hope you have enjoyed reading over this short guide and found the answers you need. If you have learned something new, please share our look into how much caffeine is in Diet Coke on Facebook and Twitter.

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Featured Image Credit: NeONBRAND, Unsplash


Ed Malaker

Ed Malaker, a veteran writer, has contributed to a wide range of blogs that cover tools, pets, guitars, fitness, and computer programming, and of course, coffee. He drinks a lot of it when he writes, making him an expert indeed. When he’s not writing, Ed is usually performing DIY projects around the house or working in the garden. He’s also a musician and spends a lot of time helping people fix their guitars and composing music for independent films.

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