Watermelon is about 91% water, but it still brings a modest dose of vitamin C — roughly 8.1 mg per 100 g of fresh red flesh. This calculator converts any serving size — grams, ounces, diced cups, or wedges — into milligrams of vitamin C and shows what that contributes to a chosen daily reference target.
Use it for quick diet planning, label comparisons, or meal tracking. Select an age- and life-stage-appropriate reference value, or stick with the FDA Daily Value of 90 mg. The tool also estimates how much watermelon you would need to eat to meet your full vitamin C target.
Because watermelon is naturally low in calories (about 30 kcal per 100 g) and high in water, it can fit comfortably into many healthy eating patterns — just do not expect it to replace higher-vitamin-C fruits like oranges. This is a helpful planning estimate, not a medical recommendation.
🍉 Watermelon Vitamin C Calculator
Estimate vitamin C from a serving of raw watermelon and compare it with a daily reference target.
How It Works
Raw watermelon is roughly 91% water, yet the edible red flesh still carries a measurable amount of vitamin C — commonly reported at about 8.1 mg per 100 g in USDA FoodData Central. This calculator converts your chosen serving size into grams and applies that nutrient density to estimate the vitamin C in your portion.
The result shows the estimated milligrams of vitamin C, the share of your selected reference target, and how much watermelon would be needed to reach the full target on its own. An optional comparison with a medium orange puts the number in everyday context, making it easy to compare watermelon with other fruits or plan a snack that moves you closer to your target.
Worked Examples
Example 1: One metric cup of diced watermelon weighs about 152 g. Estimate: 152 × 8.1 ÷ 100 = 12.3 mg. Against the 90 mg Daily Value, that is roughly 14% of the target.
Example 2: A medium wedge of about 286 g provides roughly 23 mg, or 26% of the 90 mg Daily Value — a meaningful contribution from a single summer portion.
Both examples assume fresh, raw fruit. Actual values vary slightly by variety, ripeness, and growing conditions, so treat the output as a planning estimate.
Reference Data
The reference targets below reflect common dietary guidance. The FDA Daily Value for vitamin C is 90 mg for adults and children aged 4 years and older.
| Reference | Vitamin C target |
|---|---|
| FDA Daily Value (adults and children 4+) | 90 mg |
| Adult female | 75 mg |
| Pregnant | 85 mg |
| Lactating | 120 mg |
| Teen 14–18 | 65 mg |
| Medium orange | ~70 mg |
Tips & Best Practices
Vitamin C is sensitive to heat, light, and oxygen. The freshest raw watermelon has the highest measured levels, while prolonged storage and exposure to air slowly reduce the content. Keep cut melon refrigerated in a sealed container and use it within a few days for the best quality.
Frequently Asked Questions
Can watermelon replace an orange for vitamin C? Not efficiently. You would need about 1.1 kg of fresh watermelon — roughly 7 cups of diced fruit — to match the vitamin C in one medium orange.
Is watermelon considered a good source of vitamin C? It is a modest contributor rather than a concentrated source. One large wedge can supply around a quarter of the daily target, which is genuinely useful for many people during summer months.
Does cutting or storing watermelon affect vitamin C? Yes. Exposure to air and warmth gradually lowers vitamin C levels, so the estimate is most accurate for fresh raw flesh eaten soon after cutting.
What about watermelon juice or frozen chunks? Processing, heating, and longer storage can all reduce vitamin C content, so skip the calculator and use a food database for packaged products.
Additional Resources
For authoritative nutrient data, see the USDA FoodData Central entry for raw watermelon at fdc.nal.usda.gov and the National Institutes of Health Office of Dietary Supplements vitamin C fact sheet at ods.od.nih.gov. Both sources are updated regularly and free to use.