How Much Oxalate Is in Butter?
mg oxalate
per serving
Serving: 1 tbsp (14 g)
Verdict: 🟢 Safe
Per 100g: 2 mg
Data: Harvard T.H. Chan SPH (2024)
The bottom line for Butter: 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 Butter 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 Butter 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. Applied to Butter: 0 mg oxalate per 1 tbsp — Safe per Harvard (2024).
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. Butter comes in at 0 mg oxalate per 1 tbsp (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 context, Butter measures 0 mg per 1 tbsp, rated Safe.