Radishes are a crisp, low-calorie vegetable that adds a peppery bite to salads, crudité platters, and Asian dishes. Although they're not a calcium powerhouse, they do contribute a measurable amount of this essential mineral when you eat them regularly. A 100 g serving of raw common radish supplies about 25 mg of calcium, while daikon contains slightly more — around 27 mg per 100 g.
This calculator makes it easy to estimate the calcium content of any amount of radish you're eating, whether you prefer to measure in grams, ounces, cups of sliced radish, or standard 85 g servings. It also shows the percentage of the FDA Daily Value (%DV) based on a 1,300 mg calcium target, so you can see how your radish snack fits into your overall nutrition plan.
Just select the radish type, enter an amount, and press Calculate. The step-by-step result area breaks down the math so you can trust the numbers or adjust them for your own recipes.
⚙️ Enter Your Radish Amount
Quick Start
Using the calculator takes less than a minute. Start by selecting which radish you're working with: common red or white radishes or daikon. Then enter the amount you actually plan to eat. If you are measuring for a recipe, weigh the trimmed, raw radish portion on a kitchen scale — this is the most accurate method. If you don't have a scale, use the volume-based presets: ½ cup of sliced radish is roughly 58 g and 1 cup is about 116 g.
- Choose the radish variety in the dropdown menu.
- Enter your measured amount.
- Pick the matching unit (grams, ounces, cups sliced, or 85 g servings).
- Click Calculate Calcium to see the result and step-by-step math.
The result panel shows calcium in your portion, the per-100 g value, the per-serving value, and the percentage of the 1,300 mg Daily Value.
The Math Behind It
This calculator uses nutrient reference values expressed as milligrams of calcium per 100 grams of raw radish. The formula is simple:
Calcium (mg) = (grams of radish × calcium per 100 g) ÷ 100
For common red/white radishes, the per-100 g figure is 25 mg; for daikon it is 27 mg. If you measure in ounces, the tool first converts ounces to grams using 1 oz = 28.35 g. If you measure in cups or servings, it converts using standard portion weights: 1 cup sliced = 116 g and 1 serving = 85 g. The %DV is then calculated against the FDA reference daily value of 1,300 mg for calcium. Raw nutrient values are published by USDA FoodData Central and are the same figures used by most diet tracking apps.
Worked Examples
Example 1: 1 cup of sliced red radishes.
116 g × 25 mg/100 g ÷ 100 = 29.0 mg calcium.
As a %DV: 29 ÷ 1,300 × 100 = 2.2%.
Example 2: 5 ounces of daikon.
5 oz × 28.35 = 141.75 g.
141.75 g × 27 mg/100 g ÷ 100 = 38.3 mg calcium.
As a %DV: 38.3 ÷ 1,300 × 100 = 2.9%.
Neither portion is a major calcium source by itself, but when radishes are eaten alongside high-calcium foods they still contribute to your daily total.
Reference Table
| Measured portion | Typical weight | Calcium (common radish) |
|---|---|---|
| 1 medium radish (about 1 inch diameter) | 4.5 g | 1.1 mg |
| 1 large radish (about 1.25 inch diameter) | 9 g | 2.3 mg |
| 1 oz | 28.35 g | 7.1 mg |
| ½ cup sliced | 58 g | 14.5 mg |
| 1 cup sliced | 116 g | 29.0 mg |
| 1 standard serving | 85 g | 21.3 mg |
For daikon, multiply the common-radish values by 1.08 because daikon contains about 27 mg per 100 g instead of 25 mg.
Tips for Accurate Tracking
- Weigh radishes before trimming if you plan to eat the whole root; trim first and use the edible portion if your recipe discards the stem and tail.
- Use grams whenever possible. Cups are convenient but packed slices can vary by 10–20%.
- Calcium doesn't disappear when radishes are cooked, but water loss means 100 g of cooked radish is a slightly denser portion. Use raw weights for recipes that specify cooked amounts.
- Don't expect radishes to cover your calcium needs alone. A 1,300 mg target is roughly 45–60 whole radishes' worth of calcium, so pair them with dairy, fortified plant milks, tofu, or leafy greens.
- If you're tracking for a specific diet, log the variety you actually ate — daikon and common radishes differ by about 8%, which matters over large weekly portions.
Frequently Asked Questions
Are radishes a good source of calcium? They are not a concentrated source, but they're a low-calorie, crunchy way to add a small amount of calcium and other minerals. A cup of sliced radishes has only about 29 mg of calcium and roughly 18–20 calories.
Do radish greens have more calcium? Yes. Radish leaves are considerably richer in many nutrients. This calculator focuses on the commonly eaten root; if you eat the greens, treat them like a dark leafy green and look up their separate calcium value.
Does cooking change the calcium content? The mineral itself is heat-stable. Cooking can change water content, so cooked radishes have a higher nutrient density by weight, but the same amount of calcium remains in the food.
How does this compare with other plant foods? Many vegetables have similar or higher calcium levels. For more plant-based comparisons, see our