Starbucks London Fog has more caffeine than Sprite on both counts: 40mg per 16 oz grande (40mg at every size) against 0mg per 12 oz can, and about 2mg per fluid ounce against 0. 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.
Starbucks London Fog vs Sprite: the numbers
| Starbucks London Fog | Sprite | |
|---|---|---|
| Caffeine per serving | 40mg per 16 oz grande (40mg at every size) | 0mg per 12 oz can |
| Caffeine per fl oz | 2.5mg | 0.0mg |
| Servings to reach 400mg (FDA context) | 10.0 | n/a (caffeine-free) |
Sources: Starbucks London Fog's figure is verified in our Starbucks London Fog caffeine guide against Starbucks nutrition listing (source); Sprite's figure is verified in our Sprite guide against Caffeine Informer (source).
The concentration gap is the striking part: Starbucks London Fog packs roughly 250 times the caffeine per ounce. Sipping speed matters at that density; a 16 oz grande (40mg at every size) finished in minutes hits differently than the same milligrams spread over a slow cup.
Which one should you pick?
Pick Sprite when you want the lighter dose or a slower ramp, and Starbucks London Fog 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
- Starbucks London Fog: the full caffeine guide
- Sprite: the full caffeine guide
- The verified caffeine database
FAQ
Does Starbucks London Fog or Sprite have more caffeine? Starbucks London Fog: 40mg per 16 oz grande (40mg at every size) versus 0mg per 12 oz can for Sprite.
Which is stronger per ounce? Starbucks London Fog, at about 2.5mg per fluid ounce versus 0.0mg for Sprite.
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.