How Much Oxalate Is in Oysters?
mg oxalate
per serving
Serving: 3 oz (85 g)
Verdict: 🟢 Safe
Per 100g: 0 mg
Data: Harvard T.H. Chan SPH (2024)
In practical terms, Oysters is a low-risk food for kidney stone patients. Its 0 mg oxalate per serving stays under the 25 mg line, so it can appear in your regular rotation without extra calculation. As always, staying hydrated and getting dietary calcium supports stone prevention.
Among seafood, Oysters sits well below the category average of 2 mg. For context, 55 out of 55 seafood (100%) are rated 🟢 Safe (under 25 mg oxalate/serving). The average seafood in our database has 2 mg oxalate per serving — which means Oysters is 100% below the category norm. Within its specific category, Oysters 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 seafood 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. Oysters comes in at 0 mg oxalate per 3 oz (Safe) in the measured database.
How accurate is the oxalate measurement?
These values come from Harvard's 2024 ion-chromatography analysis — the gold-standard method for oxalate. Real measured data rather than estimates. Sample-to-sample variation exists, but no published source is more dependable for food oxalate. For context, Oysters measures 0 mg per 3 oz, rated Safe.
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. Applied to Oysters: 0 mg oxalate per 3 oz — Safe per Harvard (2024).