A standard 16-ounce milk tea contains roughly 50 to 100 mg of caffeine, depending on the tea base. That puts it somewhere between a cup of green tea and a cup of coffee. The exact number shifts considerably based on which tea is used, how strong it’s brewed, and how much milk dilutes the final drink.
Caffeine by Tea Base
The single biggest factor in your milk tea’s caffeine content is which tea goes into it. Here’s how the most common bases compare per 8-ounce serving of brewed tea, before milk is added:
- Black tea: 40–70 mg. This is the default base for classic milk tea, Hong Kong-style milk tea, and most boba shop “original” or “classic” options. It delivers the most caffeine of the standard steeped teas.
- Oolong tea: 30–50 mg. A popular choice for lighter, more aromatic milk teas. Caffeine falls in the middle of the range.
- Green tea: 20–30 mg. Jasmine green tea, one of the most common milk tea bases, lands here as well.
- Matcha: 38–176 mg. Matcha is ground whole tea leaves rather than steeped leaves, so you consume the entire leaf. A typical milk tea serving uses about 1 to 2 teaspoons of matcha powder, which puts most drinks in the 50–100 mg range, though a heavy pour can push it much higher.
- White tea: 15–20 mg. Less common in milk tea but the lowest-caffeine option among true teas.
Most boba shops serve 16- or 24-ounce drinks, not 8-ounce cups. A 16-ounce black milk tea uses a concentrated tea brew that’s then diluted with milk and ice, so the caffeine in the finished drink typically lands between 50 and 100 mg. A 24-ounce version can creep higher.
Why the Same Order Can Vary So Much
Two black milk teas from two different shops can have noticeably different caffeine levels. The brewing process matters almost as much as the tea variety itself.
Steeping time is a major variable. A quick 1- to 2-minute steep pulls less caffeine from the leaves, while a 3- to 5-minute steep extracts significantly more. Many boba shops brew large batches of concentrated tea and hold them for hours, which means the base is often stronger than what you’d make at home. The tea-to-water ratio amplifies this: more leaves per batch means more caffeine in every cup.
Ice and milk then dilute that concentrate. A drink that’s half ice will have less caffeine per sip than a hot milk tea made with the same base. Ordering “less ice” gives you more tea and, by extension, more caffeine. Similarly, choosing a creamier drink with more milk reduces the proportion of tea in the cup.
Caffeine-Free and Low-Caffeine Options
Not every drink on a boba menu contains caffeine. Taro milk tea, chocolate milk tea, and most fruit-based smoothies are typically made without a true tea base, which means they contain little to no caffeine. If the purple or brown color comes from flavoring powder or paste rather than brewed tea, the caffeine is essentially zero.
Decaffeinated tea is another option, though it’s not truly caffeine-free. Decaf tea retains about 2 mg per cup, roughly 96% less than the regular version. Few boba shops stock decaf bases, but it’s straightforward to make at home.
Herbal “teas” like chamomile, rooibos, or pure fruit infusions contain no caffeine at all since they don’t come from the tea plant.
Does Milk Change How Caffeine Affects You?
Adding milk doesn’t reduce the amount of caffeine in your drink. It dilutes the concentration per ounce (since milk replaces some of the tea volume), but the total milligrams remain the same. Research on whether milk proteins alter how your body absorbs caffeine is still limited. One review in Food Science and Biotechnology noted that milk’s protein structure stays intact when it interacts with caffeine, but no strong evidence shows it meaningfully speeds up or slows down absorption.
Matcha is sometimes described as providing a “slower” caffeine release than coffee or black tea. This is likely related to other compounds in the tea leaf rather than the milk itself.
How Milk Tea Compares to Coffee
A standard 16-ounce brewed coffee contains around 180–200 mg of caffeine, roughly double what’s in most milk teas. A shot of espresso has about 63 mg, so a milk tea made with black tea is comparable to a single-shot latte. Matcha milk tea with a generous serving of powder can approach or match a double-shot espresso drink.
For context, the FDA considers up to 400 mg of caffeine per day a safe amount for most adults. A single milk tea with a standard black or oolong base uses up roughly 15–25% of that daily budget. Even two large milk teas in a day would keep most people well within that limit, though adding other caffeine sources like coffee or energy drinks narrows the margin quickly.
Estimating Your Drink’s Caffeine
Most boba chains don’t list caffeine on their menus, so you’ll need to estimate based on what you order. A few quick rules of thumb:
- Black tea base, 16 oz: ~50–100 mg
- Oolong base, 16 oz: ~40–70 mg
- Green or jasmine green base, 16 oz: ~25–50 mg
- Matcha base, 16 oz: ~50–120 mg
- Taro, chocolate, or fruit base (no tea): ~0 mg
Ordering regular ice and a higher milk ratio brings you toward the lower end of each range. Ordering less ice, no milk substitution, or asking for an extra-strong brew pushes you toward the higher end. If you’re sensitive to caffeine or drinking one in the evening, a green tea base or a non-tea flavor is your safest bet.