SToK Extra Bold cold brew has more caffeine than Starbucks London Fog on both counts: 170mg per 12 oz serving against 40mg per 16 oz grande (40mg at every size), and about 14mg per fluid ounce against 2. The serving sizes differ, so the table below shows both ways of counting.
These are different categories of drink, which changes how the caffeine arrives. Energy drinks and sodas list an exact number because caffeine is a measured additive; brewed drinks vary with the beans and the brew, so their figures are compiled averages. The numbers here are the standard published values for each.
SToK Extra Bold cold brew vs Starbucks London Fog: the numbers
| SToK Extra Bold cold brew | Starbucks London Fog | |
|---|---|---|
| Caffeine per serving | 170mg per 12 oz serving | 40mg per 16 oz grande (40mg at every size) |
| Caffeine per fl oz | 14.2mg | 2.5mg |
| Servings to reach 400mg (FDA context) | 2.4 | 10.0 |
Sources: SToK Extra Bold cold brew's figure is verified in our SToK Extra Bold cold brew caffeine guide against SToK FAQ (source); Starbucks London Fog's figure is verified in our Starbucks London Fog guide against Starbucks nutrition listing (source).
The concentration gap is the striking part: SToK Extra Bold cold brew packs roughly 6 times the caffeine per ounce. Sipping speed matters at that density; a 12 oz serving finished in minutes hits differently than the same milligrams spread over a slow cup.
Which one should you pick?
Pick Starbucks London Fog when you want the lighter dose or a slower ramp, and SToK Extra Bold cold brew when you actually need the bigger hit and know your tolerance. If you are stacking either with other caffeinated drinks through the day, run the math against the 400mg reference rather than guessing.
For context, the FDA cites 400mg of caffeine a day as an amount generally not associated with negative effects in healthy adults. Tolerance and health vary, so treat these numbers as information, not advice.
Related reading
- SToK Extra Bold cold brew: the full caffeine guide
- Starbucks London Fog: the full caffeine guide
- The verified caffeine database
- Every drink compared: the comparisons index
FAQ
Does SToK Extra Bold cold brew or Starbucks London Fog have more caffeine? SToK Extra Bold cold brew: 170mg per 12 oz serving versus 40mg per 16 oz grande (40mg at every size) for Starbucks London Fog.
Which is stronger per ounce? SToK Extra Bold cold brew, at about 14.2mg per fluid ounce versus 2.5mg for Starbucks London Fog.
Comparing caffeine? The caffeine comparison tool puts hundreds of drinks side by side, and the caffeine curfew calculator can check your cutoff time for tonight.