Tea Caffeine Calculator

Use these tools to look up how much caffeine is in your tea. Look up caffeine in green tea, oolong tea, black tea, and now Starbucks Teas, and more!

Two great caffeine tools for you to chose from: 

The Tea Caffeine Calculator has a wide selection of loose leaf teas as well as Starbucks caffeine content for tea. Use this if you want a quick lookup of how much caffeine you are drinking right now. 

The Advanced Tea Caffeine Calculator is for the loose leaf tea fan and allows you to select tea type, serving size, and the number of steeps. Use this if you multi-steep loose leaf tea. 

Ounce to Milliliter Serving Conversion
Ounce Size 8oz 12oz 16oz 20oz
Milliliter Size 237ml 355ml 473ml 591ml
Starbucks Size Short Tall Grande Venti


Caffeine varies with water temperature, tea type, steep time, roast, growing conditions, and extraction method.

Teas brewed at ratio of 1:50 (grams/ml) boiling water to tea leaves, steeped for 6 minutes. Cold brew, 4 hours.