How Much Oxalate Is in Mackerel (Cooked)?
mg oxalate
per serving
Serving: 4 oz (113 g)
Verdict: 🟢 Safe
Per 100g: 1 mg
Data: Harvard T.H. Chan SPH (2024)
What this means: Mackerel (Cooked) is rated Safe (🟢). At 1 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 seafood, Mackerel (Cooked) sits 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 Mackerel (Cooked) is 36% below the category norm. Within its specific category, Mackerel (Cooked) 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?
Per-100g values put every food on the same scale, which is handy when serving sizes differ a lot between foods — or when your portion doesn't match the standard serving. It lets you compare apples to apples on oxalate density. Applied to Mackerel (Cooked): 1 mg oxalate per 4 oz — Safe per Harvard (2024).
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. For Mackerel (Cooked), the measured oxalate value is 1 mg per 4 oz (Safe).
How does this compare to other foods?
Anything under 25 mg per serving is Safe; 25-99 mg is Caution; 100 mg or more is Avoid. The category pages on OxalateWatch list foods side by side, so you can see where this one ranks. Applied to Mackerel (Cooked): 1 mg oxalate per 4 oz — Safe per Harvard (2024).