How Much Oxalate Is in Tomatoes?
mg oxalate
per serving
Serving: 1/2 cup (121 g)
Verdict: 🟢 Safe
Per 100g: 9 mg
Data: Harvard T.H. Chan SPH (2024)
In practical terms, Tomatoes is a low-risk food for kidney stone patients. Its 11 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 vegetables, Tomatoes sits well below the category average of 27 mg. For context, 219 out of 271 vegetables (80%) are rated 🟢 Safe (under 25 mg oxalate/serving). The average vegetables in our database has 27 mg oxalate per serving — which means Tomatoes is 60% below the category norm. Within its specific category, Tomatoes 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 vegetables rated Safe to compare within the same verdict level.
Why does oxalate per 100g matter?
Normalizing to 100 grams removes serving-size differences, so you can judge which food is genuinely denser in oxalate. It matters most when you eat a bigger or smaller portion than the listed serving. Tomatoes comes in at 11 mg oxalate per 1/2 cup (Safe) in the measured database.
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. For context, Tomatoes measures 11 mg per 1/2 cup, 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. Applied to Tomatoes: 11 mg oxalate per 1/2 cup — Safe per Harvard (2024).