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How Much Caffeine in Diet Coke?

hand holding a can of diet coke

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.

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.

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.


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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