Almonds are one of the highest-oxalate foods you can eat, with about 122 mg of oxalate in a single one-ounce serving (roughly 22 almonds). Since most kidney stones are made of calcium oxalate, this makes almonds a real concern for anyone with a history of stones. For people who’ve never had a kidney stone, the occasional handful is unlikely to cause problems on its own.
Why Oxalate in Almonds Matters
About 80% of kidney stones are calcium oxalate stones. They form when oxalate in your urine binds with calcium and crystallizes. The more oxalate your body absorbs from food, the more ends up in your urine, and the higher your risk of forming these crystals.
A 2025 study tested whether almonds could reliably raise urinary oxalate levels in healthy volunteers. Almond consumption led to a consistent and significant increase in urinary oxalate, while chocolate (another food often flagged as high-oxalate) did not produce a meaningful change. The researchers specifically noted the need to inform kidney stone patients about almonds’ potential to promote stone formation.
That said, only about half of the oxalate in your urine comes from food. The rest is produced by your liver as a normal byproduct of metabolism. This means diet is just one piece of the puzzle, but it’s the piece you can most easily control.
How Much Oxalate Is Too Much
For people trying to prevent kidney stones, the University of Chicago’s kidney stone program recommends staying below 100 mg of oxalate per day, with an ideal target around 50 mg if you can manage it. A single ounce of almonds contains 122 mg, which exceeds both of those thresholds in one snack. Even a small handful can use up your entire daily oxalate budget.
If your overall diet calcium is at least 800 mg per day and you eat higher-oxalate foods alongside calcium-rich foods, staying under 150 mg of daily oxalate is considered acceptable. But almonds make it very difficult to stay within any of these ranges without cutting oxalate from nearly everything else you eat that day.
Roasting and Soaking Don’t Help Much
You might wonder if preparing almonds differently could lower their oxalate content. While boiling and soaking can reduce oxalate in some foods (because oxalate dissolves in water), research has found that the oxalate content of roasted almonds is not significantly affected by processing. The same applies to roasted cashews and peanuts. So buying roasted almonds or soaking raw almonds at home won’t meaningfully change the oxalate load.
Almond Milk Is a Different Story
Commercial almond milk contains far less oxalate than whole almonds because it’s mostly water with a small amount of almond content. A cup of Silk Almond Milk Original contains about 27 mg of oxalate, compared to 122 mg in an ounce of whole almonds. That’s still the highest oxalate level among plant-based milks (cashew, hazelnut, and soy milks all have less), but it’s a fraction of what you’d get from eating actual almonds. If you enjoy almond flavor but need to watch oxalate, almond milk is a far safer option.
Pairing Almonds With Calcium
When you eat calcium-rich foods alongside high-oxalate foods, the calcium binds to oxalate in your gut before it gets absorbed into your bloodstream. This means less oxalate reaches your kidneys. Mayo Clinic recommends including calcium-rich foods or beverages at each meal as a strategy to lower oxalate absorption.
Almonds themselves contain about 93 mg of calcium per ounce, which provides some built-in protection. But that amount of calcium isn’t enough to offset 122 mg of oxalate. If you’re going to eat a small portion of almonds despite the risk, pairing them with yogurt, cheese, or milk could help reduce how much oxalate your body absorbs. This isn’t a free pass, though. It reduces the impact rather than eliminating it.
Lower-Oxalate Nut Alternatives
The National Kidney Foundation specifically flags almonds, mixed nuts with peanuts, and sesame seeds as high-oxalate choices. If you’re looking for nuts that fit a low-oxalate diet, several options contain far less oxalate per serving:
- Macadamia nuts are among the lowest-oxalate tree nuts
- Pecans contain moderate oxalate but significantly less than almonds
- Walnuts fall in the moderate range
- Pumpkin seeds and flaxseeds are lower-oxalate seed options
Switching to these alternatives lets you keep nuts in your diet without the outsized oxalate hit that almonds deliver.
Who Actually Needs to Worry
If you’ve never had a kidney stone and don’t have a family history of them, eating almonds in reasonable amounts as part of a varied diet is unlikely to cause problems on its own. Kidney stones form from a combination of factors: low fluid intake, high sodium, low dietary calcium, and genetics all play roles alongside oxalate consumption.
The people who should be most cautious are those who’ve already formed calcium oxalate stones, those with malabsorptive conditions (like Crohn’s disease or a history of gastric bypass surgery) that increase oxalate absorption, and anyone whose doctor has identified high urinary oxalate as a specific risk factor. For these groups, almonds are one of the most impactful single foods to reduce or eliminate. Replacing your daily almond snack with a lower-oxalate nut and keeping fluid intake high can meaningfully lower your stone risk without overhauling your entire diet.