brewed oolong tea vs Starbucks London Fog: which has more caffeine?

Starbucks London Fog carries more total caffeine per serving (40mg per 16 oz grande (40mg at every size) vs 37mg per 8 oz cup), but ounce for ounce brewed oolong tea is actually the stronger drink at about 5mg per fluid ounce against 2. Which one "has more caffeine" depends on whether you measure the container or the concentration.

brewed oolong tea vs Starbucks London Fog: the numbers

Sources: brewed oolong tea's figure is verified in our brewed oolong tea caffeine guide against USDA FoodData Central (source); Starbucks London Fog's figure is verified in our Starbucks London Fog guide against Starbucks nutrition listing (source).

Which one should you pick?

Pick brewed oolong tea 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

• brewed oolong tea: the full caffeine guide
• Starbucks London Fog: the full caffeine guide
• The verified caffeine database
• Every drink compared: the comparisons index

FAQ

Does brewed oolong tea or Starbucks London Fog have more caffeine? Starbucks London Fog: 40mg per 16 oz grande (40mg at every size) versus 37mg per 8 oz cup for brewed oolong tea.

Which is stronger per ounce? brewed oolong tea, at about 4.6mg per fluid ounce versus 2.5mg for Starbucks London Fog.