Are walnuts high in oxalate?
C
Moderately. Moderate, 12 mg per 1 oz (about 14 halves)
Range 12 to 12 mg across 1 study, 28 g serving
0 mg50 mg = a day60 mg+
Lower-oxalate swap: Pistachios, grade B, about 9 mg per 1 oz (about 49 nuts).
Walnuts have a moderate amount of oxalate: about 12 mg per 1 oz (about 14 halves), which is 24% of the 50 mg a day many stone clinics aim for.
Where this number comes from
Each row is one published measurement, converted to a 28 g serving (1 oz (about 14 halves)). 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 |
|---|---|---|---|
| 12 mg | 41.3 mg | as sold | Harvard T.H, 2023 |
| 12 mg | 41.79 mg | Raw | Harvard T.H, 2023 |
By Oliver Silen · Data checked November 2, 2026 · Not medical advice