A single ounce of black olives (about 7 to 8 olives) contains roughly 25 to 26 calories. That makes them one of the lowest-calorie snacks you can grab, though the exact count shifts depending on the variety and how they’re prepared. Per 100 grams, canned black olives come in at about 116 calories.
Calories by Serving Size
Most nutrition labels list black olives with a one-ounce (28-gram) serving size, which works out to about 25 to 26 calories. In practice, that’s roughly 7 to 8 medium olives from a can. A quarter-cup serving is close to one ounce. If you’re tossing a handful into a salad or eating them straight from the jar, you’re likely consuming somewhere between 25 and 50 calories depending on how generous the handful is.
Individual olives vary in size quite a bit. The USDA grades canned ripe olives from “small” (about 16 mm across, with 128 to 140 per pound) all the way up to “super colossal” (26 mm or larger, 40 or fewer per pound). A single large olive weighs around 4 to 5 grams and contains roughly 5 calories. A jumbo or colossal olive can be double that weight and closer to 8 to 10 calories each.
What Else Is in That Serving
Nearly all the calories in black olives come from fat. A one-ounce serving has about 4.4 grams of total fat, most of it the monounsaturated kind (the same heart-friendly fat found in olive oil and avocados). Protein is negligible, and carbohydrates are minimal. You do get about 1.8 grams of dietary fiber per ounce, which is surprisingly high for such a small, low-calorie food. That fiber content is one advantage whole olives have over olive oil, which contains zero fiber.
Kalamata vs. Canned California Olives
The standard canned black olives you find in most American grocery stores are California ripe olives, picked green and then oxidized to turn black during processing. Kalamata olives, the dark purple ones common in Mediterranean dishes, are a different variety altogether. Nutritionally, they’re similar. A serving of about 6 to 8 Kalamata olives has around 35 calories and 2.5 grams of fat.
The bigger differences show up in flavor, texture, and sodium. Kalamata olives are typically brined or packed in oil, which can add slightly more fat per serving. Oil-cured black olives (the wrinkly, intensely flavored kind) tend to be more calorie-dense than water-cured or canned varieties because the curing process concentrates their natural fats. If you’re tracking calories closely, canned California black olives are generally the lightest option.
The Sodium Factor
Sodium is the main nutritional concern with black olives. Just a quarter-cup (about one ounce) delivers roughly 23% of the 2,300-milligram daily sodium limit used on U.S. nutrition labels. If you’re aiming for the American Heart Association’s stricter target of 1,500 milligrams per day, that same small serving accounts for about 35% of your daily budget.
This is why most nutrition guidance suggests keeping your intake to a small handful, around 5 to 10 olives per day. Rinsing canned olives under water before eating them can reduce some of the surface sodium, though it won’t remove what’s absorbed during processing.
Antioxidants Worth Knowing About
Black olives contain a powerful antioxidant compound called hydroxytyrosol, which is considered one of the strongest antioxidants found in any food. The European Food Safety Authority has recognized it as protective for the cardiovascular system, specifically for its ability to prevent the oxidation of LDL (“bad”) cholesterol, a key step in the development of artery-clogging plaque.
Hydroxytyrosol also reduces inflammation by blocking the enzymes that drive inflammatory responses. Research has shown it can cross the blood-brain barrier, where it protects brain cells from a type of damage linked to age-related cognitive decline. Olives also contain oleuropein, another antioxidant that works alongside hydroxytyrosol. These compounds are present in olive oil too, but whole olives deliver them packaged with fiber, which slows digestion and may help you feel fuller than the equivalent calories from oil alone.
How Black Olives Fit Into Your Diet
At roughly 25 calories per ounce, black olives are easy to work into almost any eating pattern. They add flavor and fat to salads, pasta, and grain bowls without significantly increasing your calorie total. Because their fat is predominantly monounsaturated, they align well with Mediterranean-style eating, where healthy fats replace saturated sources rather than being added on top of them.
The practical limit isn’t calories but sodium. Five to ten olives a day gives you the antioxidant and flavor benefits without pushing your salt intake into uncomfortable territory. If you eat olives alongside other high-sodium foods like cheese, cured meats, or soy sauce, it’s worth keeping a rough mental tally for the day.