Oolong Tea Calories Explained (Per Cup Breakdown)

If you’ve ever wondered whether oolong tea actually has calories, you’re not alone. Some sources say zero, others say a little. The short answer? Plain, brewed oolong tea has virtually no calories - typically just 1-2 calories per 8-oz cup. 

Oolong tea sits between green tea and black tea, so people often assume it must be different nutritionally. That’s why this question comes up so often for anyone focused on weight loss or fasting.

In this guide, we’ll break down how many calories are actually in oolong tea, and when calories start to appear. You’ll also know how oolong tea calories compare to other popular teas.

Oolong Tea Calories in Plain Oolong Tea

Plain oolong tea contains about 0-2 calories per 8-ounce (240 ml) cup. That’s when it’s brewed with just tea leaves and water, with nothing added.

This is true because tea leaves don’t contain sugar, fat, or starch in a form your body can use for energy. When you brew oolong tea, you’re mostly pulling out flavor, aroma, and natural plant compounds - not calories.

That’s why different oolongs taste different, from light and floral to creamy or toasty. Here’s what a typical cup of plain oolong tea looks like nutritionally:

ou’ll sometimes see the phrase “trace calories” used. This doesn’t mean oolong tea suddenly contains hidden energy. It just refers to tiny natural compounds from the tea leaves. 

Just like polyphenols and amino acids, which dissolve into the water during brewing. They don’t raise blood sugar, they don’t fuel your body, and they don’t meaningfully affect calorie intake.

Because of this, drinking plain oolong tea does not add calories in any practical sense. It contains no fat, protein, or carbohydrates, making it an excellent low-calorie beverage choice.

However, the calorie content rises significantly when ingredients like sugar, milk, or sweeteners are added. In fact, sweetened oolong milk tea can contain hundreds of calories, depending on the amount and type of additions used.

Calories in Oolong Tea by Preparation Type

This is where most of the confusion about calories comes from. Oolong tea itself is very low in calories. But the number can change quickly depending on how it’s prepared and what’s added to the cup.

The easiest way to think about it is this: plain oolong tea is the baseline. Every other version starts there and adds calories on top.

Plain Oolong Tea

• Calories: 1-2 per 8 oz cup

• Add-ins: None

• Fasting-compatible: Yes

Plain oolong tea is just tea leaves and hot water. That’s it. Because there’s no sugar, fat, or starch involved, the calorie count stays near zero.

This is the version people are referring to when they say oolong tea is “zero calorie.” It’s also the version used in nutrition databases and calorie trackers. You can drink multiple cups throughout the day and still not meaningfully increase your calorie intake.

This is the version people are referring to when they say oolong tea is “zero calorie.” If you prefer drinking oolong tea plain, styles like Mountain Praise or Dong Ding oolong work exceptionally well. They are flavorful on their own without needing sugar or milk.

Exploring different varieties like loose-leaf oolong or oolong tea bags can also make it easy to stick with plain brewed tea.

Sweetened Oolong Tea

• Calories: Increase based on how much sugar is added

• Source of calories: Sugar, honey, syrups

Once a sweetener enters the picture, the calories are no longer coming from the tea. They’re coming entirely from the sugar.

Even a small amount can make a difference. A teaspoon of sugar may not sound like much. But it turns a zero-calorie drink into something that now counts toward daily energy intake. The more sweetener added, the higher the calorie count climbs.

This is why you’ll see different calorie numbers online for oolong tea. Some sources are talking about plain tea, while others are referring to sweetened versions without making that clear.

Oolong Milk Tea

• Calories: Moderate to high

• Source of calories: Milk, cream, plant milks, and sugar

Milk tea still uses oolong tea as the base, but the calories come from everything mixed into it. Dairy milk adds calories from fat and lactose, while plant-based milks like oat or soy often add calories from carbs.

Many milk tea recipes also include sugar or sweetened condensed milk. It pushes the calorie count even higher. Depending on how it’s made, an oolong milk tea can go from a light drink to something closer to a dessert.

It’s also worth clearing up a common point of confusion. Milk oolong, such as Jin Xuan No. 12, is a type of oolong tea that naturally tastes creamy, even without adding milk or sugar.

When brewed plain, milk oolong has the same near-zero calories as other plain oolong teas. The higher calories only appear when actual milk or sweeteners are added.

Bottled Oolong Tea

• Calories: Highly variable

• Often contains: Added sugar

Bottled oolong tea is where things get especially tricky. Even when the label says “tea,” many bottled versions are sweetened to improve taste and shelf life.

Some bottles contain only a small amount of sugar, while others have as much as soda or juice. Because of this, calorie counts can vary widely from brand to brand.

If you’re buying bottled oolong tea, the label matters more than the name. Always check the nutrition facts, especially the sugar line.

Quick Comparison (Per 8 oz)

If calories matter to you, plain oolong tea is the clear winner. The moment sugar, milk, or bottling enters the picture, the calorie count depends entirely on what’s been added - not on the tea itself.

Is Oolong Tea High in Calories?

No - oolong tea is not high in calories. When it’s brewed plain, it’s one of the lowest-calorie drinks you can have.

What helps is looking at oolong tea next to standard drinks people actually consume. On its own, oolong tea is closer to water than it is to juice or soda. That’s why it’s so often recommended as a swap for higher-calorie beverages.

Here’s a simple comparison to put things into perspective:

Compared to soda or juice, oolong tea is basically calorie-free. Even compared to coffee, it’s just as low as long as nothing is added. And like green tea, its calorie count stays near zero because it’s just brewed leaves and water.

So if you’re choosing drinks with calories in mind, plain oolong tea lands firmly in the “very low” category. Any time it becomes higher-calorie, it’s because of what’s added - not because of the tea itself.

Is Oolong Tea Healthy for Weight Loss?

There can be some oolong tea health benefits, but they tend to show up in indirect ways. It’s not a fat-burning shortcut, and it does not magically change your metabolism.

Where oolong tea helps most is in calorie balance. Plain oolong tea has almost no calories. That’s why it works well as a replacement for higher-calorie drinks like soda, juice, or sweetened coffee. When your daily energy intake goes down, weight loss becomes easier to maintain over time.

Oolong tea also contains caffeine, which can help with alertness and focus. For some people, that means better energy during workouts or fewer afternoon cravings.

That said, caffeine alone doesn’t guarantee weight loss, and the effect varies from person to person. What’s important to be clear about:

• Oolong tea does not burn fat on its own

• It does not guarantee metabolic changes

• Any benefit comes from smarter drink choices, not the tea doing the work for you

So yes, oolong tea can fit nicely into a weight-loss routine. Just think of it as a low-calorie tool, not a solution on its own.

Can You Drink Oolong Tea While Fasting?

For most people, yes - plain oolong tea is generally fasting-friendly. When it’s brewed with just tea and water, it has virtually no calories. So, it doesn’t meaningfully affect insulin or energy intake.

The key thing to watch out for is add-ins. Sugar, honey, milk, cream, or flavored syrups do break a fast because they add calories and can trigger an insulin response. Once those are in the cup, it’s no longer just tea.

One more thing to keep in mind is caffeine. Oolong tea caffeine is moderate compared to other teas, making it suitable for many people. However, if caffeine makes you feel jittery or uncomfortable, it may be better to limit your intake or switch to a caffeine-free tea.

Bottom line: plain oolong tea is fine during a fast. Just keep it simple, and pay attention to how your body responds.

How Many Calories Are in Oolong Tea Per Day?

It depends entirely on how you drink it, not how much tea you enjoy.

If you’re drinking plain oolong tea, the calories stay near zero even across multiple cups. One cup has about 1-2 calories, so several cups spread throughout the day still don’t add up to anything meaningful.

For example:

• 3-5 cups of plain oolong tea: still roughly 0-10 calories total

• Even more cups: calories remain negligible as long as nothing is added

Things change once sweeteners or milk are introduced. Calories from sweetened or milk-based oolong tea do accumulate. It happens because those calories come from sugar and milk, not the tea itself.

A simple way to think about it:

• Plain oolong tea: calories don’t really add up

• Sweetened or milk tea: calories stack with every serving

So when it comes to daily intake, serving size matters far less than add-ins. Keep oolong tea plain, and you don’t need to worry about calories adding up.

Oolong Tea vs Green Tea (Calories & Nutrition)

When it comes to calories, oolong tea and green tea are basically the same. Both have about 1-2 calories per 8-ounce cup when brewed plain. So, there’s no real difference calorie-wise.

The main difference comes from oxidation, which affects how the tea is processed - not how many calories it has. Green tea is minimally oxidized, while oolong tea is partially oxidized. This changes the taste and aroma, but it doesn’t add calories.

Flavor is where most people notice the contrast. Green tea tends to taste lighter, grassier, or fresher. Oolong tea often has a richer flavor that can be floral, toasty, or slightly creamy, depending on the variety.

Caffeine levels are similar but not identical. Green tea usually has a bit less caffeine, while oolong tea falls in the middle range. Either way, caffeine adds no calories, so this difference doesn’t affect nutrition. It just comes down to taste and how your body responds.

Bottom line: if you’re choosing between oolong tea and green tea for calorie reasons, you can’t really go wrong. Pick the one you enjoy drinking more, because nutritionally, they’re almost identical.

Frequently Asked Questions

People often have common questions when it comes to oolong tea calories. Here are some common questions answered to understand properly: 

Where can I buy high-quality oolong tea?

High-quality oolong tea comes from trusted sources that focus on freshness and origin. Dong Po Tea offers a curated selection of loose-leaf and tea-bag oolongs, suited for brewing plain.

Is oolong tea high in calories?

No. Plain oolong tea is very low in calories, with about 1-2 calories per 8-ounce cup. As long as nothing is added, it’s considered a zero-calorie drink for everyday use.

How many calories are in oolong tea for weight loss?

If you’re drinking it plain, oolong tea adds almost no calories, even if you have multiple cups a day. It works well for weight loss mainly because it replaces higher-calorie drinks, not because it burns fat.

Can I drink oolong tea every day?

Yes, most people can drink oolong tea daily without any issues. Just keep an eye on caffeine if you’re sensitive, and avoid loading it up with sugar or milk if calories are a concern.

Does caffeine add calories?

No. Caffeine has zero calories. It can affect alertness and energy levels, but it doesn’t add to your calorie intake on its own.

How many calories are in iced oolong tea?

Iced oolong tea has the same calories as hot oolong tea when it’s brewed plain. Temperature doesn’t change the calorie content - only added sugar or flavorings do.

Final Thoughts

Oolong tea calories are virtually zero when the tea is brewed plain, and that’s the simple truth. With just tea leaves and water, oolong tea doesn’t meaningfully add to daily calorie intake.

Where calories do show up is with add-ins. Sugar, milk, and bottled versions change the picture quickly, and those calories come from what’s added - not the tea itself.

Because of that, oolong tea fits easily into many dietary routines, including calorie tracking, weight loss, and fasting. Keep it plain, and you can enjoy it freely without overthinking the numbers.