How Much Oxalate Is in Blackberry?
mg oxalate
per serving
Serving: 1 cup (144 g)
Verdict: 🟢 Safe
Per 100g: 4 mg
Data: Harvard T.H. Chan SPH (2024)
What this means: Blackberry is rated Safe (🟢). At 6 mg oxalate per serving, it's well under the 25 mg safety threshold. You can include it regularly in a kidney stone diet. Pair it with calcium-rich foods (dairy, fortified plant milks) for additional protection, and drink plenty of water throughout the day.
Among fruits, Blackberry sits well below the category average of 21 mg. For context, 101 out of 113 fruits (89%) are rated 🟢 Safe (under 25 mg oxalate/serving). The average fruits in our database has 21 mg oxalate per serving — which means Blackberry is 72% below the category norm. Within its specific category, Blackberry ranks among the lower-oxalate options. This context matters because two 'Safe' foods can have very different oxalate levels — one might have 5 mg while another has 24 mg. Both are Safe, but the first gives you more dietary flexibility. Browse all fruits rated Safe to compare within the same verdict level.
Why does oxalate per 100g matter?
The per-100g number lets you compare foods on an equal-weight basis, regardless of serving size. It's useful when two foods have very different typical serving sizes, or when you eat more or less than a standard serving.
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.
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.