How Much Oxalate Is in hard-boiled?
mg oxalate
per serving
Serving: 2 large (100 g)
Verdict: 🟢 Safe
Per 100g: 0 mg
Data: Harvard T.H. Chan SPH (2024)
The bottom line for hard-boiled: Safe (🟢), with 0 mg oxalate per serving — comfortably below the 25 mg safe cutoff. There's no need to limit it. Just keep your usual kidney stone basics in place: water throughout the day and calcium-rich foods at meals.
Putting hard-boiled in context: it lands well below the category average of 3 mg. In the database, 95% of dairy & eggs (87 of 91) fall in the 🟢 Safe group (under 25 mg oxalate/serving). The typical dairy & eggs here averages 3 mg oxalate per serving, so hard-boiled runs 100% below that baseline. That places it among the lower-oxalate options in its category. Why this matters: the gap between two Safe foods can be wide — one may hold 5 mg oxalate while another sits at 24 mg. The lower one leaves more room in your day. See all dairy & eggs rated Safe for a full side-by-side.
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. For hard-boiled, the measured oxalate value is 0 mg per 2 large (Safe).
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. hard-boiled comes in at 0 mg oxalate per 2 large (Safe) in the measured database.
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. For hard-boiled, the measured oxalate value is 0 mg per 2 large (Safe).