Is dark chocolate high in oxalate?
Yes. Very high, 87 mg per 1.5 oz bar
Range 67 to 107 mg across 2 studies, 42 g serving
Lower-oxalate swap: Milk chocolate, grade B, about 6.9 mg per 1.5 oz bar.
Dark chocolate is high in oxalate: about 87 mg per 1.5 oz bar, which is 174% of the 50 mg a day many stone clinics aim for, or 87% of the 100 mg others allow.
If your doctor has put you on a low-oxalate diet, eat it with something high in calcium, like milk, yogurt or cheese. Calcium in the same meal binds oxalate in the gut, so less of it reaches your urine. How much calcium, and what if you don't eat dairy.
50 or 100 mg a day: which target is yours
Why sources disagree on dark chocolate
Oxalate in chocolate follows the cocoa. A 2011 survey of 34 commercial chocolates from 13 countries reached 254 mg per 100 g, and Harvard's bar measured 159. Milk chocolate has much less cocoa, and Harvard measured it at 16.5 mg per 100 g.
Where this number comes from
Each row is one published measurement, converted to a 42 g serving (1.5 oz bar). The grade and the range use the rows prepared the way the serving is eaten, and take the middle. How the grades work.
| Per serving | Per 100 g | Preparation | Source |
|---|---|---|---|
| 67 mg | 159.2 mg | bar | Harvard T.H, 2023 |
| 107 mg | 254 mg | commercial, 34 samples, 13 countries (n=34) | Schroder T, Vanhanen L, Savage GP, 2011 |
By Oliver Silen · Data checked November 2, 2026 · Not medical advice