Pepsi Zero Sugar Caffeine: 38 mg vs Pepsi, Diet Pepsi
Pepsi Zero Sugar Caffeine: 38 mg vs Pepsi, Diet Pepsi
Pepsi Zero Sugar has 38 mg of caffeine per 12 oz can, according to PepsiCo's product facts page. That is the same as regular Pepsi. A 20 oz bottle has 63 mg. Diet Pepsi is slightly lower at 35 mg per 12 oz, and Coca-Cola Zero Sugar has 34 mg. If you want a zero-sugar cola with the least caffeine, Coke Zero wins by 4 mg per can.
| Situation | Pick | Why |
|---|---|---|
| Lowest caffeine in a zero-sugar cola | Coke Zero Sugar | 34 mg per 12 oz, 4 mg less than Pepsi Zero Sugar |
| Zero-sugar cola, zero caffeine | Coca-Cola Zero Sugar Caffeine Free | 0 mg; Pepsi.com lists no caffeine-free Pepsi Zero Sugar |
| Matching regular Pepsi's caffeine, no sugar | Pepsi Zero Sugar | Same 38 mg per 12 oz as regular Pepsi |
| More caffeine in a zero-sugar soda | Mountain Dew Zero Sugar | 68 mg per 12 oz, nearly double Pepsi Zero Sugar |
Pepsi Zero Sugar vs Pepsi vs Diet Pepsi vs Coke Zero
| Drink | 12 oz caffeine | 20 oz caffeine | Per fl oz | Caffeine-free version? | Pick it if... |
|---|---|---|---|---|---|
| Pepsi Zero Sugar | 38 mg | 63 mg | 3.2 mg | No | You want full Pepsi taste, zero sugar |
| Pepsi | 38 mg | 63 mg | 3.2 mg | Yes (Pepsi Caffeine Free) | You prefer regular sugar cola |
| Diet Pepsi | 35 mg | 59 mg | 2.9 mg | Yes (Diet Pepsi Caffeine Free) | You want a Pepsi cola with a bit less caffeine |
| Diet Pepsi Wild Cherry | 38 mg | 63 mg | 3.2 mg | Not listed | You want cherry flavor at full Pepsi caffeine |
| Coca-Cola Zero Sugar | 34 mg | not published | 2.8 mg | Yes (Coke Zero Caffeine Free) | You want the lowest-caffeine zero-sugar cola |
| Mountain Dew Zero Sugar | 68 mg | 113 mg | 5.7 mg | Not listed | You want almost twice Pepsi Zero's caffeine |
Source: pepsicoproductfacts.com caffeine table and coca-cola.com, checked Oct 31, 2026.
How we compared
Every milligram figure in this article comes from PepsiCo's own product facts caffeine table and Coca-Cola's product page. Per-fl-oz values and daily-limit math were computed from those numbers; no cans were lab-analyzed for this page. One thing to know up front: Roon sells a caffeine pouch, which appears near the end of this page, and every soda figure here comes from the brands' own published labels, so you can check it yourself.
Pepsi Zero Sugar Caffeine by Size
PepsiCo publishes caffeine for every package size of Pepsi Zero Sugar. The concentration holds at about 3.1 to 3.2 mg per fl oz across sizes.
| Package | Serving | Caffeine |
|---|---|---|
| Mini can | 7.5 fl oz | 24 mg |
| Standard can | 12 fl oz | 38 mg |
| Bottle | 13 fl oz | 41 mg |
| Tall can / bottle | 16 fl oz | 50 mg |
| Bottle | 16.9 fl oz | 53 mg |
| Bottle | 20 fl oz | 63 mg |
| 2-liter bottle | 67 fl oz (per 12 fl oz serving) | 38 mg |
| Fountain | 12 fl oz | 38 mg |
PepsiCo notes on its caffeine page that it voluntarily labels caffeine "from all sources" on caffeinated drinks. The numbers above apply to the current US formula.
Does Pepsi Zero Sugar Have More Caffeine Than Regular Pepsi?
No. PepsiCo lists the same caffeine for both at every size: 38 mg per 12 oz can, 63 mg per 20 oz bottle, 50 mg per 16 oz.
Some websites and older databases still list 69 mg per 12 oz for Pepsi Zero Sugar. PepsiCo's current caffeine table lists 38 mg. If a third-party site says 69 mg, check the can, which carries PepsiCo's own caffeine figure.
Do the Flavored Pepsi Zero Sugar Cans Have Caffeine?
Yes, all flavored Pepsi Zero Sugar varieties carry the same caffeine as the original. Per PepsiCo's table:
- Wild Cherry: 38 mg (12 oz), 50 mg (16 oz), 53 mg (16.9 oz), 63 mg (20 oz)
- Mango: 38 mg (12 oz), 63 mg (20 oz)
- Vanilla & Cream: 38 mg (12 oz), 63 mg (20 oz)
- Wild Cherry & Cream: 38 mg (12 oz), 63 mg (20 oz)
Switching flavors within the Pepsi Zero Sugar line does not change your caffeine intake.
Is There a Caffeine-Free Pepsi Zero Sugar?
As of Oct 2026, Pepsi.com lists Pepsi Caffeine Free and Diet Pepsi Caffeine Free, but no caffeine-free version of Pepsi Zero Sugar. If you need a zero-sugar, zero-caffeine cola from PepsiCo, Diet Pepsi Caffeine Free is the closest option (Pepsi.com describes it as "zero caffeine"; it is sold as "Diet" rather than "Zero Sugar").
On the Coca-Cola side, Coca-Cola Zero Sugar Caffeine Free does exist, and Coca-Cola lists it with no caffeine.
How Many Cans of Pepsi Zero Sugar Is Too Much Caffeine?
The FDA cites 400 mg per day as an amount not generally associated with negative effects for most adults. At 38 mg per 12 oz can:
400 ÷ 38 = ~10.5 cans (12 oz) or 400 ÷ 63 = ~6.3 bottles (20 oz)
That sounds like a lot of soda, but caffeine stacks from every source: coffee, tea, energy drinks, chocolate, supplements. Two 20 oz Pepsi Zero Sugars alone add up to 126 mg, about a third of the daily figure, before any coffee.
If you are pregnant, trying to become pregnant or breastfeeding, the FDA advises talking to your healthcare provider about caffeine.
Which Cola Should You Pick?
- Want the lowest caffeine in a zero-sugar cola? Coca-Cola Zero Sugar, at 34 mg per 12 oz.
- Want zero caffeine from Pepsi? Pepsi Caffeine Free or Diet Pepsi Caffeine Free. Neither is a "Zero Sugar" branded product.
- Want more caffeine in a soda? Mountain Dew Zero Sugar delivers 68 mg per 12 oz, nearly double Pepsi Zero Sugar.
- Want zero sugar and a longer caffeine window than soda? (our product, not ranked) Roon is a caffeine pouch with 80 mg per pouch, zero sugar, with a felt duration of 6 to 8 hours. From $9.16 per tin.
Related from Roon
- Does Coke Zero Have Caffeine? The Exact Amount, Explained
- How Much Caffeine Is in Coke?
- Does Sprite Have Caffeine?
Frequently Asked Questions
Does Pepsi Zero have more caffeine than Coke Zero?
Yes, slightly. Pepsi Zero Sugar has 38 mg per 12 oz can; Coca-Cola Zero Sugar has 34 mg per 12 oz. The gap is 4 mg per can. See the full Coke Zero caffeine breakdown for more size comparisons.
How much caffeine is in a 20 oz Pepsi Zero?
A 20 fl oz bottle of Pepsi Zero Sugar has 63 mg of caffeine, per PepsiCo's caffeine table. That is the same as a 20 oz regular Pepsi. Diet Pepsi in the same size has 59 mg.
How much caffeine is in a fountain Pepsi Zero Sugar?
PepsiCo lists 38 mg per 12 fl oz fountain serving of Pepsi Zero Sugar, the same concentration as the canned version. Fountain cup sizes vary by restaurant, so a 20 oz fountain fill would scale to about 63 mg.
What sweeteners are in Pepsi Zero Sugar?
The ingredients list includes aspartame and acesulfame potassium as the two non-nutritive sweeteners, per the product label. The can also carries the notice "Phenylketonurics: Contains Phenylalanine" because aspartame is a source of phenylalanine.
Does Pepsi Zero Sugar break a fast?
It has no sugar (it is sweetened with aspartame and acesulfame potassium), so whether it fits depends on how strict your fast is. For a deeper look at how diet sodas interact with fasting, see Does Diet Coke Break a Fast?.
Caffeine That Lasts Past the Last Sip
A 12 oz Pepsi Zero Sugar gives you 38 mg of caffeine, and when the can is gone it is easy to reach for a second. If you would rather get more time out of one dose than drink more volume, the ingredient that matters is not the caffeine itself.
Roon is a zero-nicotine, zero-sugar caffeine pouch that sits under the lip, with 80 mg of caffeine plus L-theanine, theacrine and 25 mg of methylliberine. Methylliberine slows how fast the body clears caffeine: in a randomized, double-blind crossover PK study (n=12), it stretched caffeine's half-life from 7.2 to 15 hours and cut oral clearance from 41.9 to 17.1 L/hr without raising the peak (study), though that study used 100 mg methylliberine with 150 mg caffeine, about 4x and 1.9x what one Roon pouch holds, so only the direction carries over. A 15-hour half-life is not 15 hours of felt energy; people typically feel a pouch for 6 to 8 hours, so leave at least 8 hours between your last pouch and bedtime.
It is not a soda replacement and it is not a nicotine product. Roon is from $9.16 per tin on a 12-tin subscription, 15 pouches per tin. If you want one measured caffeine dose without drinking anything, Roon is worth a look.
Sources
- PepsiCo Product Facts: Caffeine
- Coca-Cola Zero Sugar product page
- Pepsi.com products
- H-E-B: Pepsi Zero Sugar ingredients
- FDA: Spilling the Beans (caffeine guidance)
- Caffeine and methylliberine: a human pharmacokinetic interaction study (Journal of Exercise and Nutrition)
Written by Roon Team
