The short answer
An alkaline foods list is a list of foods with a negative PRAL score. PRAL stands for potential renal acid load. It is an estimate, published by Thomas Remer and Friedrich Manz in 1995, of how much acid or base a food leaves for the kidneys to clear once it has been digested. Vegetables, fruits and potatoes usually score below zero, which is what people mean when they call a food alkaline. Cheese, meat, fish, eggs and many grains score above zero.
This page gives the numbers for 30 foods we actually cook with. The values are our own calculations from USDA FoodData Central nutrient data, using the Remer and Manz formula, and the method is explained below so you can check any food yourself. Published PRAL tables use older nutrient data and will not match ours to the decimal, so treat the numbers as a ranking, not a lab result.
One thing PRAL does not measure is the pH of your blood. Your body holds blood pH in a narrow range, roughly 7.35 to 7.45, whatever you eat, as a 2012 review in the Journal of Environmental and Public Health explains. Remer and Manz tested PRAL against urine pH, and urine is where diet shows up. On this site, alkaline is a lifestyle and recipe label for plant-forward cooking, not a promise to change your body chemistry.
How the chart was calculated
Remer and Manz estimated a food's acid load from five nutrients, each measured per 100 grams. Protein and phosphorus push the score up, because the body breaks them down into acids. Potassium, magnesium and calcium pull it down. The formula is: PRAL (mEq per 100 g) = 0.49 × protein (g) + 0.037 × phosphorus (mg) − 0.021 × potassium (mg) − 0.026 × magnesium (mg) − 0.013 × calcium (mg).
For every food in the chart we took those five values from USDA FoodData Central, using the SR Legacy record for the plain food (raw unless the label says cooked or baked) and ran the formula. A negative result means the food is estimated to be base-forming. A positive result means it is estimated to be acid-forming. The bigger the number, the stronger the estimated effect for that 100-gram portion.
Two limits matter. First, 100 grams is a weighing convenience, not a serving: almost nobody eats 100 grams of raisins at once, and plenty of people eat 200 grams of potato. Second, PRAL leaves out things such as sulfur-containing amino acids and how well each mineral is absorbed, which is why Remer and Manz called it a potential acid load. It is a useful way to compare foods, and that is all we use it for here.
The PRAL chart, most alkaline to most acid
Values are mEq per 100 grams, calculated from USDA FoodData Central. The minus sign means base-forming, which is the sense of alkaline used on most food lists.
Vegetables
Every vegetable we checked came out below zero: Spinach, raw −11.8; sweet potato, baked −8.2; kale, raw −8.0; potato, raw −6.6; carrots, raw −5.7; cauliflower, raw −4.4; tomato, raw −4.1; broccoli, raw −4.0; cucumber, raw −2.4. Leafy greens lead because they are rich in potassium and magnesium and low in protein. Note that kale's high calcium also pulls its score down.
Fruits
Fruit sits on the alkaline side too: Raisins −14.5; avocado, raw −8.2; banana, raw −6.9; orange, raw −3.6; strawberries, raw −2.5; lemon, raw −2.3; apple, raw, peeled −1.5. Raisins rank first on the whole chart because drying concentrates potassium. Gram for gram, a lemon is milder than a banana. It tastes sour because of citric acid, but the PRAL calculation counts what the minerals and protein leave after digestion, not the taste.
Near neutral: legumes, nuts, dairy and whole grains
These foods land within a few points of zero: Tofu, firm +0.1; yogurt, plain, whole milk +0.1; milk, whole +0.2; lentils, cooked +2.1; almonds +2.3; brown rice, cooked +2.3; chickpeas, cooked +2.6; whole-wheat bread +4.5; walnuts +5.6. Beans and lentils carry protein and phosphorus, but their potassium and magnesium mostly cancel it out. Milk and plain yogurt sit almost exactly at zero because their calcium and potassium offset their protein.
Acid-forming: eggs, fish, meat, cheese and dry oats
The highest scores belong to concentrated protein foods: Egg, raw +9.6; rolled oats, dry +9.8; salmon, farmed, cooked +11.1; chicken breast, roasted +17.3; cheddar cheese +17.3. Rolled oats appear here because the value is for dry oats, which are dense in phosphorus. Cooked oatmeal is mostly water and scores much lower per 100 grams. Hard cheese and lean meat score highest because they pair a lot of protein with a lot of phosphorus.
Reading the chart without overreading it
Acid-forming does not mean bad, and alkaline does not mean good. Salmon, eggs, oats and yogurt are part of healthy eating patterns in the Dietary Guidelines for Americans. The chart says nothing about vitamins, fiber or protein quality. It answers one narrow question: given a food's protein and minerals, which way does it tip the acid load?
What matters is the whole plate, because PRAL adds up. A bowl that is mostly vegetables and potatoes with some chickpeas and a little cheese can still come out below zero overall. That is why the practical advice here looks like ordinary plant-forward cooking advice: make vegetables and fruit the largest part of the plate and use the richer protein foods as part of the meal, not all of it.
If an alkaline food list has no numbers, ask what it is measuring. Lists without numbers can mix up two things: a food's own pH in the jar and what it leaves behind after digestion. Lemon juice is acidic in the jar, yet lemon scores below zero here. Only the second measurement is the one Remer and Manz described.
Putting the list in the kitchen
The easiest way to cook from the alkaline end of the chart is to build meals around potatoes, greens, beans and fruit, then season well. A few recipes on this site do exactly that. The lemon herb chickpea garden bowl pairs near-neutral chickpeas with a pile of vegetables and herbs. The ginger lime vegetable soup is a pot of the vegetables from the top of the chart. The cucumber pear green smoothie adds fruit and greens to breakfast.
Swaps that move the plate down the chart
Add a second vegetable side instead of a second protein. Use a smaller portion of cheese and add avocado for richness. Make roasted potatoes or sweet potatoes the base of the plate instead of an extra roll. Snack on fruit, or on raisins in small amounts, instead of cheese and crackers. None of these swaps needs special products, and every ingredient is in an ordinary grocery store.
Where to go next
Our food-first approach to alkaline eating explains how this site uses the word alkaline. The plant-forward week built on MyPlate turns the chart into seven dinners. For the other end of the chart, our acidic foods list gives PRAL values for 35 cheeses, meats, fish, nuts, grains and drinks. If you want to check the numbers for a food that is not listed, our guide to looking up nutrition in USDA FoodData Central shows where to find the five nutrients the formula needs.
Medical disclaimer
Medical disclaimer: this article is general food education for a recipe audience. It does not provide medical advice, diagnosis, or treatment, and it does not claim that any food on this list changes blood pH or prevents, treats, or cures any disease. Alkaline, on this site, is a lifestyle and recipe label for food. People with kidney disease or anyone told to limit potassium or protein should follow their own clinician's advice before changing what they eat, because many foods at the alkaline end of this chart are high in potassium. Please also read the full disclaimer on this site.
Sources
Remer T, Manz F. Potential renal acid load of foods and its influence on urine pH. Journal of the American Dietetic Association. 1995;95(7):791–797. https://pubmed.ncbi.nlm.nih.gov/7797810/
Schwalfenberg GK. The alkaline diet: is there evidence that an alkaline pH diet benefits health? Journal of Environmental and Public Health. 2012. https://pmc.ncbi.nlm.nih.gov/articles/PMC3195546/
U.S. Department of Agriculture, Agricultural Research Service. FoodData Central (SR Legacy records for each food listed; protein, phosphorus, potassium, magnesium and calcium per 100 g). https://fdc.nal.usda.gov/
U.S. Department of Agriculture and U.S. Department of Health and Human Services. Dietary Guidelines for Americans, 2020–2025. https://www.dietaryguidelines.gov/
A thoughtful note: This article is for general education and inspiration. It does not provide medical advice, diagnosis, or treatment. Please see our full disclaimer.