Does oolong tea have caffeine?

Yes — oolong has caffeine, about 30–50 mg per 8 oz cup (avg ~40 mg), between green and black tea. Published figures and what actually changes the number.

By PGP Iyer · July 29, 2026 · 4 min read

Yes — oolong tea has caffeine. A typical 8 oz cup runs about 30–50 mg (avg ~40 mg), sitting between green tea and black tea. Published figures vary by source: Healthline puts a cup at 38 mg, while Medical News Today reports a range of 29–53 mg per 8 fl oz. Oolong's caffeine comes from the tea leaf itself, not from how dark or light the leaf was oxidized.

How much caffeine is in oolong tea?

Oolong sits in the middle of the true-tea caffeine spectrum — more than white tea, roughly level with green tea, and somewhat below black tea. Healthline's nutrition data puts a cup of oolong at 38 mg of caffeine, compared with about 29 mg for a cup of green tea in the same source. Medical News Today gives a wider published band of 29 to 53 mg per 8-fl-oz serving. Both figures land inside the 30–50 mg range this site uses as its working reference for oolong, with an average of about 40 mg.

What is oolong tea?

Oolong is tea leaf from Camellia sinensis — the same plant behind green, black, white, and matcha — that has been partially oxidized, somewhere between green tea (minimally oxidized) and black tea (fully oxidized). Oxidation is a controlled browning process the leaf undergoes after picking, and it's what determines which broad tea category a leaf becomes: Medical News Today notes that “the more tea leaves oxidize, the darker they become, which determines the type of tea.” A “light” oolong might be oxidized closer to 10–20%, tasting and looking closer to green tea, while a “dark” oolong can be oxidized 60–80% or more, tasting and looking closer to black tea. That's a wide spread within a single tea category.

Does oxidation level change oolong's caffeine?

Not in a direct, predictable way. Oxidation reliably changes color, aroma, and flavor — that's its whole job in tea processing — but it isn't the lever that sets caffeine content. Caffeine is present in the fresh leaf before oxidation ever starts, and what actually moves the final cup's number is closer to leaf grade, growing conditions, and how the tea is brewed (see below), the same factors that create ranges within green and black tea too. That's a large part of why light and dark oolongs both fall inside roughly the same published band instead of splitting into two very different numbers the way you might expect from such different-looking teas.

Oolong vs. green tea vs. black tea caffeine

Use the calculator above to compare oolong against any other drink by the cup or across a full day, or check the static reference table below:

The pattern across sources is consistent even where the exact numbers differ: oolong sits above white and roughly level with or a little above green tea, and below black tea. It never lands near coffee's 80–100 mg range or matcha's more concentrated 60–80 mg.

What changes oolong's caffeine

• Leaf grade and pluck. Younger leaves and buds generally carry more caffeine than older, more mature leaves — a difference in the raw material, not the oxidation step.
• Steep time and water temperature. A longer steep or hotter water pulls more caffeine out of the same leaves. See our how to brew oolong tea guide for gongfu vs. Western steeping and how each affects strength.
• Leaf-to-water ratio. More leaf per cup means a stronger, more caffeinated brew, independent of oxidation level.
• Light vs. dark oolong style. Style affects flavor and aroma far more than it affects caffeine — don't assume a darker, more roasted-tasting oolong is automatically higher in caffeine.
• Decaf oolong. Decaffeinated oolong exists and has most, not all, of its caffeine removed through processing.

Is oolong's caffeine a lot?

At roughly 30–50 mg per 8 oz cup, oolong is a modest share of the general daily reference the U.S. FDA has cited — about 400 mg per day as a level not generally associated with negative effects for most healthy adults. That reference covers everything caffeinated you drink in a day, not any single cup, so it's worth counting oolong alongside coffee, other tea, and anything else caffeinated you have that day. People who are pregnant, caffeine-sensitive, or managing a health condition should talk to a healthcare provider about what caffeine level is appropriate for them.

For how oolong compares to matcha and green tea specifically, see our matcha caffeine and green tea caffeine pages. For oolong's other studied compounds, see oolong tea benefits.

This describes published research and general information, not medical or dietary advice.