How Much Oxalate Is in Flour?

A standard serving of Flour (1/4 cup, about 34g) contains 66 mg of oxalate. That works out to roughly 193 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 66 mg, Flour falls in the Caution category.

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

66
mg oxalate
per serving

Food: Flour, Teff, Ivory
Serving: 1/4 cup (34 g)
Verdict: 🟡 Caution
Per 100g: 193 mg
Data: Harvard T.H. Chan SPH (2024)

🔄 Lower-Oxalate Alternatives

💡 What This Means for Your Diet

What this means: Flour is rated Caution (🟡). At 66 mg oxalate per serving, Flour is in the moderate zone (25-99 mg). It's manageable with portion awareness — try smaller servings, less frequent consumption, and pairing with calcium-rich foods. Track total daily oxalate to stay under ~100 mg.

📊 How Flour Compares

Among grains & pasta, Flour sits well above the category average of 14 mg. For context, 170 out of 201 grains & pasta (84%) are rated 🟢 Safe (under 25 mg oxalate/serving). The average grains & pasta in our database has 14 mg oxalate per serving — which means Flour is 375% above the category norm. Within its specific category, Flour ranks on the higher end for oxalate. 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 grains & pasta rated Caution 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.