How Much Oxalate Is in flour (white)?
mg oxalate
per serving
Serving: 1 tortilla (45 g)
Verdict: 🟢 Safe
Per 100g: 2.2 mg
Data: Harvard T.H. Chan SPH (2024)
In practical terms, flour (white) is a low-risk food for kidney stone patients. Its 1 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 grains & pasta, flour (white) sits well below 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 (white) is 93% below the category norm. Within its specific category, flour (white) 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 grains & pasta 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. Applied to flour (white): 1 mg oxalate per 1 tortilla — Safe per Harvard (2024).
How accurate is the oxalate measurement?
The measurements use ion chromatography, the accepted reference method for oxalate. That means real lab values for each food rather than inferred numbers. Some natural variation exists between samples, but this is the strongest published data set. For context, flour (white) measures 1 mg per 1 tortilla, rated Safe.
How does this compare to other foods?
The ratings split at 25 mg (Safe) and 100 mg (Avoid), with 25-99 mg in the Caution band. For context against similar foods, the category pages on OxalateWatch rank every item in that group by oxalate. For context, flour (white) measures 1 mg per 1 tortilla, rated Safe.