How Much Oxalate Is in Apple?

A standard serving of Apple (1 medium, about 182g) contains 1 mg of oxalate. That works out to roughly 0 mg per 100 grams. These numbers are direct lab measurements from Harvard T.H. Chan School of Public Health (2024), via the OHF database. For context, the safe threshold for kidney stone patients is 25 mg per serving. Based on its 1 mg, Apple falls in the Safe category.

✓ Medically Reviewed Based on Harvard T.H. Chan SPH oxalate data (2024) and NKF/AUA dietary guidelines.

1
mg oxalate
per serving

Food: Apple, red delicious, raw with skin
Serving: 1 medium (182 g)
Verdict: 🟢 Safe
Per 100g: 0 mg
Data: Harvard T.H. Chan SPH (2024)

🔄 Lower-Oxalate Alternatives

💡 What This Means for Your Diet

What this means: Apple 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.

📊 How Apple Compares

Among fruits, Apple 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 Apple is 96% below the category norm. Within its specific category, Apple 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.

❓ Related Questions

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.

This is dietary reference information, NOT medical advice. Talk to your doctor or a registered dietitian before changing your diet. Oxalate tolerance varies by person, stone type, and medication.