Wondering how much caffeine is in Coke Zero compared to other sodas?
Coke Zero is a sugar-free alternative to regular Coca-Cola, but does it still contain caffeine? The short answer: Yes, Coke Zero has caffeine—but less than a cup of coffee.
Quick Answer: How much caffeine is in Coke Zero?
Coke Zero has 34 milligrams of caffeine per 12-ounce serving, while an average cup of coffee has 80 – 100 milligrams.
If you’re looking for a caffeine-free option, Coke Zero Caffeine-Free is available.
While Coke Zero has no sugar, its artificial sweetener (aspartame) may still affect energy levels by inducing hyperactivity in some individuals.
To help compare, here’s how Coke Zero stacks up against other popular sodas:
Beverage | Caffeine (12 oz can) |
🥤 Coke Zero | 34 mg |
🥤 Regular Coca-Cola | 34 mg |
🥤 Diet Coke | 46 mg |
🥤 Pepsi Zero Sugar | 69 mg |
🥤 Sprite, Fanta (Caffeine-Free Sodas) | 0 mg |
In this guide, I’ll compare Coke Zero’s caffeine content to coffee, tea, and other sodas—so you know exactly what you’re drinking.
Let’s dive in!

Coffee vs. Coke Zero: Which has more caffeine?
Coffee has a higher caffeine content than Coke Zero.
But how much caffeine is there in Coke Zero in comparison to coffee?
An 8-ounce cup (237 ml) of coffee carries roughly 80 to 100 milligrams of caffeine, which can vary slightly between coffee brands.
Conversely, Coke Zero’s 12-ounce (355 ml) serving contains about 34 milligrams of caffeine, compared to about 21 milligrams in an 8-ounce (237 ml) serving.
Here’s a quick overview to compare the caffeine content of Coke Zero to coffee and tea:
Beverage | Caffeine |
🍵 Green Tea (8 oz) | 25 – 30 mg |
🥤 Coke Zero (12 oz) | 34 mg |
🥤 Regular Coca-Cola (12 oz) | 34 mg |
☕ Espresso (per shot) | 64 mg |
☕ Black Coffee (8 oz) | 80 – 100 mg |
Still, some coffee brands carry lower amounts of caffeine in Coke Zero, particularly if they are decaffeinated.

Coke Zero compared to different types of coffee
While Coke Zero generally has less caffeine than your average cup of joe, the comparison still depends on your coffee-drinking habits.
“Thanks for the article on how much caffeine is too much in a day!”
Decaf coffee
The average instant decaffeinated coffee only carries about 2 milligrams of caffeine (8-ounce or 237 ml serving).
Nestle’s Milo, on the other hand, has about 4 milligrams of caffeine (8-ounce or 237 ml serving).
Some restaurants’ coffee-based beverages contain slightly more caffeine than instant decaf but are still lower in caffeine than Coke Zero. All caffeine content figures are for 8-ounce servings.

Fast food coffee
Fast food coffee carries low to moderate caffeine. Arby’s Jamocha Shake, for example, only carries about 6 milligrams of caffeine.
On the other hand, Starbucks decaf coffee has a surprisingly high 12 milligrams of caffeine.
Even seemingly low-caffeine beverages in Starbucks, such as the Pink Drink and the Refreshers, carry around 22 milligrams of caffeine (for a short cup size), roughly the same as Coke Zero.

However, the caffeine content of all products mentioned so far is still considered low relative to other coffee products that actually aim to provide energy boosts to their drinkers.
Instant coffee
The average instant coffee contains about 57 milligrams of caffeine. While that’s more caffeine than Coke Zero, it’s still lower than other types of coffee.

For example, Nescafe’s 3-in-1 Instant Coffee carries around 67 milligrams of caffeine.
Turkish coffee, on the other hand, provides 200 milligrams of caffeine for an 8-ounce cup, which explains why they are served in tiny cups.
Some coffee shop beverages also have lower caffeine content, such as Dunkin’ Donuts’ Dunkaccino, which contains only about 48 milligrams.
Dalgona coffee, which has become very popular over the last few years, has a pretty high caffeine content: 105 milligrams.
Regular coffee
While a lot stronger than Coke Zero, these caffeine content figures are still considered moderate.
However, with regular coffee and more traditional coffee beverages, the difference becomes starker.

Starbucks’ cold brew, for example, contains about 104 milligrams of caffeine, while Dunkin’ Donuts’ brewed coffee has about 210 milligrams.
Finally, some products are actually geared to provide dangerous levels of caffeine.
This includes Death Wish Coffee, which has an alarming 560 milligrams, and the Black Label Brewed Coffee, which registers an unbelievable 1,038 milligrams.
This is the strongest coffee in the world.
Coke Zero can still keep you awake
Despite its low levels, the caffeine in Coke products can still keep you awake. The FDA estimates that the half-life of caffeine is about five hours.
This means that after 5 hours of taking caffeine in, half of the amount you ingested is still flowing through your veins.
The average person needs about 100 milligrams of caffeine to stay awake, so an 8-ounce serving of Coke Zero may not be enough.
What really keeps people awake with Coke products is its high amount of sugar. An 8-ounce (237 ml) serving of regular Coke carries 26 grams of sugar.

With Coke Zero, sugar is not a problem, as its primary sweetener is aspartame.
It’s 200 times sweeter than sugar, which is why they are added in such small amounts to beverages.
In fact, the very low amount of sweetener is why Coke Zero has zero calories.
However, aspartame can still affect your sleep. It can cause hyperactivity and insomnia and worsen your overall sleep quality.
Remember that Coke Zero is not primarily served in 8-ounce (237 ml) servings. Most countries have them available in 12-ounce (355 ml) cans.
Either way, the caffeine is negligible, but the aspartame may be a different story.
Side effects of caffeine
As you may know, caffeine is the most popular pick-me-up in the world. But too much of it can cause side effects, including irritability and an increase in anxiety.
Some people also report experiencing dizziness, shakiness, and insomnia.

Another problem with it is that it can cause dependency. People often increase their coffee intake to get the same kick once their bodies get accustomed to their usual dose.
However, it would take a ridiculously high amount of caffeine in short intervals for it to be lethal.
If you want to get rid of caffeine altogether and still enjoy Coke Zero, you can try the Zero Caffeine Zero Sugar variety.
Side effects of aspartame
The first thing to do when determining how healthy a product is is to look at the nutrition facts.
In addition to 0 calories, Coke Zero also contains 0 fat and 0 carbohydrates, making it a magnet for those trying to lose body fat.
But that’s not the entire picture. We also have to look at the ingredients. Carbonated water generally has the same effects as water, so it’s not much to worry about.
The effects of caramel coloring and phosphoric acid are also generally okay.
Aspartame is the one to watch, as this is an artificial sweetener. This must be avoided if you really want the weight loss to be fat reduction instead of muscle.
Aspartame can cause weight gain
Research has demonstrated how drinks heavy in artificial sweeteners, especially aspartame and sucralose, can cause the same levels of weight gain as drinks sweetened with regular sugar.
Many believe that artificial sweeteners make the consumer crave more sugar, negating any benefits of the low-calorie count.
This is because your brain is introduced to the sweet taste, yet your body receives zero energy from the low amount of aspartame.
Artificial sweeteners can raise insulin
Some research shows artificial sweeteners can raise your insulin levels, which makes fat loss more difficult.
Insulin secures the fat in the body, increasing the effort you should exert if you want to reduce it.
As such, you may be better off with other zero-calorie sodas, such as Zevia. Or, if you want, you can stick to regular coffee if it’s the caffeine kick you’re after.
If you don’t like the bitter taste of coffee, there are many ways for you to make it more enjoyable.
Make your coffee taste less bitter
Creamers and sugar are usually the way to go if you want to remove the bitterness from your coffee.
Besides bringing out the sweetness, removing the bitterness helps your tongue focus on the other flavors in coffee.
But too much sugar and creamer can be pretty unhealthy. What you can do is play with other ingredients instead.
One of my personal favorites is vanilla extract. Something about vanilla makes it go well with everything, particularly with coffee.

Vanilla extract also has that sweetness to it without the guilt that comes with sugar.
You can also play with other natural sweeteners, such as honey, which has a lot of health benefits.
Add salt if you don’t mind that extra layer of complexity in your drink.
You can also add cinnamon for an earthy, exotic flavor or mint for an extra kick of freshness.

For the creamer, you can use soy milk, oat milk, or almond milk as a substitute.
These can neutralize bitterness, and each has its own flavors you can experiment with.
You can also make your drinking experience much more enjoyable by pairing it with your favorite pastry.
If you want to treat yourself or if you’re taking a break from your diet, try this recipe for a salted caramel mocha Frappuccino. Believe me, it won’t disappoint.

FAQs about Coke Zero and caffeine
Before I close off this article, let’s quickly go over a few key questions people have when researching the caffeine content in Coke Zero.
Who knows, maybe this will answer one of the questions you had as well!
Is Coke Zero caffeine-free?
No. Coke Zero contains caffeine, but there is a caffeine-free version available.
Is Coke Zero a good alternative to coffee for caffeine?
Coke Zero has caffeine but significantly less than coffee. A regular cup of coffee has about three times more caffeine than a can of Coke Zero.
Does Coke Zero have the same caffeine as Diet Coke?
No. Coke Zero has 34 mg of caffeine per 12 oz can, while Diet Coke has 46 mg per 12 oz can.
Conclusion
If you’re looking for a better-tasting energizer than coffee, Coke Zero may not be the right choice.
It doesn’t contain nearly the same amount of caffeine and may introduce some health problems.
Make your daily dose of caffeine delicious instead by following the tips above.
Do you prefer Coke Zero, Diet Coke, or regular Coca-Cola? Let me know in the comments!
Learn more about caffeine content
Curious about the caffeine levels in other drinks? Check out my other guides here: