How Much Oxalate Is in Tofu (Firm)?
mg oxalate
per serving
Serving: 1/2 cup (126 g)
Verdict: 🟢 Safe
Per 100g: 1.6 mg
Data: Harvard T.H. Chan SPH (2024)
What this means: Tofu (Firm) is rated Safe (🟢). At 2 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 legumes, Tofu (Firm) sits well below the category average of 20 mg. For context, 44 out of 60 legumes (73%) are rated 🟢 Safe (under 25 mg oxalate/serving). The average legumes in our database has 20 mg oxalate per serving — which means Tofu (Firm) is 90% below the category norm. Within its specific category, Tofu (Firm) 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 legumes 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 Tofu (Firm): 2 mg oxalate per 1/2 cup — 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. Applied to Tofu (Firm): 2 mg oxalate per 1/2 cup — Safe per Harvard (2024).
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. Applied to Tofu (Firm): 2 mg oxalate per 1/2 cup — Safe per Harvard (2024).