Most plain brewed tea contains almost zero carbohydrates — a cup of unsweetened black or green tea typically has less than 1 gram of carbs per 100g. That number climbs quickly once sugar, honey, milk, flavored syrups, or boba pearls enter the cup. This Tea Carbs Per 100g Calculator helps you estimate the full carbohydrate load of your favorite tea drink — both per serving and per 100 grams — so you can log it accurately in keto, diabetic, or macro-tracking apps.
The calculator accounts for the most common tea additions: the base tea type, serving volume, sweeteners, milk, and even cooked boba pearls. It's built for low-carb dieters, people managing blood sugar, and anyone who wants to compare a plain glass of iced tea with a loaded milk tea. Just choose your tea base, enter your amounts, and press Calculate to see a full carb breakdown with an estimated per-100g value.
Quick Start
Here's how to get an accurate carb estimate in about a minute:
- Select your tea base from the dropdown. Plain brewed teas are nearly carb-free, while canned sweetened tea and powdered mixes start with a base carb load.
- Enter the base tea volume in milliliters. A standard mug is about 240 mL; a large iced tea cup is often 470–590 mL.
- Add sweeteners in teaspoons or milliliters. Sugar substitutes can be added too, but they typically contribute negligible digestible carbs.
- Choose a milk type and amount if your drink includes milk. Unsweetened almond milk adds very few carbs, while oat milk adds noticeably more.
- Include cooked boba pearls by weight if your drink is a bubble tea.
- Press Calculate Carbs to see total carbs and carbs per 100g.
How the Carb Math Works
The calculator estimates total carbs by adding each ingredient's contribution. For liquids, we convert milliliters to grams using a 1:1 density approximation. Sugar is estimated at 4.2 g of carbs per teaspoon, honey at 5.7 g per teaspoon, flavored syrup at 0.65 g per mL, and cooked boba pearls at 0.35 g per gram.
Total carbs = tea base carbs + sugar + honey + syrup + milk + boba
Milk carbs come from USDA nutrition data: whole milk ~4.8 g/100g, skim ~5.0 g/100g, oat ~7.0 g/100g, soy ~4.0 g/100g, unsweetened almond ~0.3 g/100g. Tea base values are also set from USDA entries for brewed black tea and green tea.
The carbs per 100g figure is then calculated as total carbs ÷ estimated drink weight × 100. This is the number that makes different tea drinks easy to compare at a glance.
Reference: Carbs in Common Tea Additions
These are approximate values used by the calculator, based on common nutrition databases such as USDA FoodData Central and typical manufacturer labels.
| Ingredient | Amount | Carbs |
|---|---|---|
| Brewed black tea | 100 g | ~0.3 g |
| Brewed green tea | 100 g | ~0 g |
| Granulated sugar | 1 tsp | 4.2 g |
| Honey | 1 tsp | 5.7 g |
| Flavored syrup | 10 mL | 6.5 g |
| Whole milk | 30 mL | 1.4 g |
| Oat milk | 30 mL | 2.1 g |
| Unsweetened almond milk | 30 mL | ~0.1 g |
| Cooked boba pearls | 30 g | 10.5 g |
Worked Example
Classic milk tea:
- 240 mL black tea: 240 × 0.3 / 100 = 0.7 g
- 3 tsp sugar: 3 × 4.2 = 12.6 g
- 60 mL whole milk: 60 × 4.8 / 100 = 2.9 g
Total carbs = about 16.2 g. Estimated weight = 240 + 60 + 12.6 = 312.6 g, so carbs per 100g ≈ 5.2 g.
If you add 80 g of cooked boba, that's another 28 g of carbs — which is why bubble teas are so carb-dense compared to plain iced tea.
When to Use This Calculator
This tool is useful for anyone comparing drinks before ordering or building a meal plan. Low-carb and keto users can quickly see that a plain iced tea is essentially free, while a medium boba milk tea can deliver 40–60 g of carbs — close to an entire day's allotment on a strict keto diet. Diabetic users can use the per-100g value to estimate portion sizes that fit their insulin or meal plan.
It also helps people who log food in apps. Instead of guessing a "medium bubble tea" entry, you can enter exact ingredient amounts and get a defensible number for your food diary.
Tips & Common Mistakes
Tip: Weigh boba and milk whenever possible. Volume estimates from cafe menus can vary by 20–30%, and that swing can change your carb count by several grams.
Mistake to avoid: Don't assume "sugar-free" always means low-carb. Some sugar-free syrups still contain sugar alcohols or maltodextrin, and oat milk is naturally higher in carbs than many people expect.
For blood-sugar management, remember that the calculator reports total carbs, not net carbs. Individual responses to sweeteners and sugar alcohols vary, so use the result as a planning tool rather than a medical guarantee.
Frequently Asked Questions
Is plain tea really carb-free? Nearly. Unsweetened brewed tea is essentially water with traces of plant compounds, so it contributes under 0.5 g per 100g in most databases. See this overview of black tea for background.
Why does the per-100g value look lower than total carbs? Because a 100g portion is only about 100 mL of liquid. A 240 mL drink weighs roughly 250–300 g once sweeteners and milk are included, so the total carbs are spread over a larger weight.
Can I use this for milk tea powder or instant chai? Partially. The "Iced tea powder mix" base option gives a rough estimate, but packaged mixes vary by brand. Check the nutrition label and adjust the base carb value if you know it.
What about sugar-free sweeteners? Stevia, erythritol, monk fruit, and sucralose contribute negligible digestible carbs in typical amounts. You can leave those rows at zero.
Additional Resources
For more precise food composition data, visit USDA FoodData Central. For a general introduction to tea types and their characteristics, the Wikipedia article on black tea and the bubble tea overview are helpful starting points.