Kombucha is a fermented tea drink that contains small amounts of potassium and other electrolytes, but the exact amount varies a lot by brand, batch, and brewing method. This Kombucha Potassium Calculator helps you estimate the potassium content in your kombucha — whether you're tracking a single 8 fl oz serving, a full bottle, or a homemade batch. Just enter your volume, choose a potassium level, and get the total in milligrams, percent Daily Value, and a handy banana-equivalent comparison.
This tool is useful for people managing potassium intake due to kidney conditions, athletes replenishing electrolytes, and anyone following a micronutrient-focused diet. Because commercial kombucha labels don't always list potassium, the calculator includes three reference levels (low, typical, high) plus a custom option when you have a brand-specific value. Use the result as a practical estimate rather than a lab measurement.
🍶 Kombucha Volume
🧪 Potassium Level
📊 Your Result
Step-by-Step Guide
Start by entering the amount of kombucha you drank or plan to drink. The calculator accepts milliliters, fluid ounces, or cups — the quick preset buttons let you fill in common serving sizes in one click. Next, choose a potassium level that matches your situation:
- Low (~10 mg/100 ml) — typical for lightly brewed or heavily filtered kombucha.
- Typical (~25 mg/100 ml) — a reasonable middle-ground estimate for many store-bought brands.
- High (~50 mg/100 ml) — closer to some robust home brews or brands that report higher potassium.
- Custom — use this if the label shows a specific potassium value. Enter the amount per 100 ml.
Press Calculate Potassium to see the total in milligrams, the percent of the Daily Value, and a banana-equivalent so you can relate the number to a familiar food.
About the Daily Value: The U.S. FDA uses 4,700 mg as the Daily Value for potassium on Nutrition Facts panels. Your personal target may be different depending on health conditions and medications, so treat this percentage as a general reference.
How It Works
The calculation is straightforward: convert your serving to milliliters, then multiply by the potassium density.
Formula: Potassium (mg) = Volume (ml) × Potassium per 100 ml ÷ 100
For example, 8 fl oz = 236.6 ml. At 25 mg/100 ml: 236.6 × 25 ÷ 100 = 59 mg.
Because kombucha is a fermented product, potassium levels are not standardized. The values used here are rounded reference estimates based on typical published ranges for tea-based fermented beverages. For a more precise number, check the brand's label or contact the manufacturer. The custom level exists for exactly this reason — if you have a verified value, it always trumps a generic estimate.
Worked Examples
- 16 fl oz bottle, typical level: 473 ml × 25 ÷ 100 = 118 mg → about 2.5% DV.
- 1 cup, high level: 237 ml × 50 ÷ 100 = 118 mg → about 2.5% DV.
- 1 liter, low level: 1000 ml × 10 ÷ 100 = 100 mg → about 2.1% DV.
As you can see, kombucha is generally not a major potassium source compared to foods like potatoes, beans, or bananas. It can still be a pleasant way to contribute a small amount of electrolytes, especially if you drink it regularly throughout the week.
Reference Data
The table below compares typical potassium amounts across common beverages and foods to give your kombucha number some context.
| Beverage or Food | Serving | Potassium (mg) |
|---|---|---|
| Kombucha (typical) | 8 fl oz (240 ml) | ~59 |
| Sports drink | 8 fl oz (240 ml) | ~45–75 |
| Coconut water | 8 fl oz (240 ml) | ~470–600 |
| Orange juice | 8 fl oz (240 ml) | ~450 |
| Low-fat milk | 8 fl oz (240 ml) | ~390 |
| Banana | 1 medium fruit | ~422 |
Values are approximate and vary by brand, ripeness, and preparation method.
Tips & Best Practices
- If you track potassium for kidney health, log kombucha consistently — but also count other sources throughout the day.
- Homemade kombucha can vary from batch to batch; test your brew or use a wider range when estimating.
- Flavored kombuchas with fruit juice or added minerals may have slightly different potassium content than plain varieties.
- Use the custom option whenever a label lists potassium — it is always more reliable than a generic estimate.
Important: This calculator provides dietary estimates and is not medical advice. If you have chronic kidney disease, are on dialysis, or take potassium-affecting medications, talk with your doctor or renal dietitian before changing your potassium intake.
Precision Notes
The reference potassium levels in this calculator are rounded estimates, not laboratory measurements. Actual values can vary by a meaningful margin, especially for homemade kombucha where brewing time, tea variety, and added ingredients all play a role. If you are using kombucha to help hit a medically prescribed potassium target, treat the estimate with caution and prefer label data or manufacturer-supplied values whenever possible.
Frequently Asked Questions
Why doesn't my kombucha label show potassium?
Potassium is an optional line on U.S. Nutrition Facts labels, so many smaller brands omit it. When it is not listed, you can contact the manufacturer or use an estimated range.
Does fermentation change potassium content?
Fermentation primarily converts sugars to acids and carbon dioxide; it does not create or destroy significant amounts of potassium. Most potassium in kombucha comes from the tea leaves and any added fruit or botanicals.
Can I drink kombucha on a low-potassium diet?
Kombucha is usually low in potassium, but portion matters. Check with your healthcare team, as individual potassium limits vary widely.
How do I convert a label value to mg per 100 ml?
Divide the listed milligrams by the serving size in milliliters, then multiply by 100. For instance, a 240 ml serving with 72 mg of potassium works out to 72 ÷ 240 × 100 = 30 mg per 100 ml.
For more detail on potassium in the diet, see the NIH Office of Dietary Supplements – Potassium.