Is watermelon high in oxalate?
A
No. Very low, <1 mg per 1 cup diced
Range <1 to <1 mg across 2 studies, 152 g serving
0 mg50 mg = a day60 mg+
Watermelon is low in oxalate: about <1 mg per 1 cup diced, which is 1% of the 50 mg a day many stone clinics aim for, or 0% of the 100 mg others allow.
50 or 100 mg a day: which target is yours
Why sources disagree on watermelon
The 2 studies here run from <1 to <1 mg per 1 cup diced, measured between 2002 and 2023. Variety, growing conditions and lab method all move the number. Every one of them lands in grade A.
Where this number comes from
Each row is one published measurement, converted to a 152 g serving (1 cup diced). 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 |
|---|---|---|---|
| <1 mg | 0.21 mg | Raw | Harvard T.H, 2023 |
| <1 mg | 0.3 mg | Raw (n=1) | Hönow R., Hesse A, 2002via Foods 2023;12:3201, Table 5 (CC BY 4.0) |
By Oliver Silen · Data checked November 2, 2026 · Not medical advice