How Much Oxalate Is in Granny smith Apple?
mg oxalate
per serving
Serving: 1 medium (182 g)
Verdict: 🟢 Safe
Per 100g: 0.5 mg
Data: Harvard T.H. Chan SPH (2024)
What this means: Granny smith 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.
Among fruits, Granny smith 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 Granny smith Apple is 96% below the category norm. Within its specific category, Granny smith 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.
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. For context, Granny smith Apple measures 1 mg per 1 medium, rated Safe.
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 Granny smith Apple, the measured oxalate value is 1 mg per 1 medium (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 Granny smith Apple: 1 mg oxalate per 1 medium — Safe per Harvard (2024).