How Much Oxalate Is in Grapes (Red or green)?
mg oxalate
per serving
Serving: 1/4 cup (37 g)
Verdict: 🟢 Safe
Per 100g: 9 mg
Data: Harvard T.H. Chan SPH (2024)
Here's the takeaway: Grapes (Red or green) earns a Safe rating (🟢) at 6 mg oxalate per serving. Being under 25 mg means it fits comfortably in everyday eating. Keep your usual habits — adequate fluids and calcium in meals — and Grapes (Red or green) poses no special concern.
Putting Grapes (Red or green) in context: it lands well below the category average of 21 mg. In the database, 89% of fruits (101 of 113) fall in the 🟢 Safe group (under 25 mg oxalate/serving). The typical fruits here averages 21 mg oxalate per serving, so Grapes (Red or green) runs 72% below that baseline. That places it among the lower-oxalate options in its category. Why this matters: the gap between two Safe foods can be wide — one may hold 5 mg oxalate while another sits at 24 mg. The lower one leaves more room in your day. See all fruits rated Safe for a full side-by-side.
Why does oxalate per 100g matter?
Normalizing to 100 grams removes serving-size differences, so you can judge which food is genuinely denser in oxalate. It matters most when you eat a bigger or smaller portion than the listed serving. For Grapes (Red or green), the measured oxalate value is 6 mg per 1/4 cup (Safe).
How accurate is the oxalate measurement?
Harvard's 2024 analysis used ion chromatography — the gold standard for oxalate measurement. These are direct lab values, not estimates or database calculations. Variability exists between samples, but this is the most reliable reference available. Grapes (Red or green) comes in at 6 mg oxalate per 1/4 cup (Safe) in the measured database.
How does this compare to other foods?
Foods under 25 mg per serving are rated Safe. Foods between 25-99 mg are Caution. 100+ mg is Avoid. Check the food's category page on OxalateWatch to see how it compares to similar foods. For Grapes (Red or green), the measured oxalate value is 6 mg per 1/4 cup (Safe).