A standard 3.75-ounce can of sardines contains roughly 21 to 23 grams of protein, depending on whether they’re packed in oil or water. That’s about 40% of the daily protein most adults need, all from a shelf-stable can that costs a couple of dollars.
Protein by Can Size and Packing Liquid
Most sardine cans sold in the U.S. come in the 3.75-ounce (about 92 grams drained) size. A 3-ounce serving of canned sardines delivers around 21 grams of protein, so a full can lands slightly higher. Per 100 grams, sardines in oil provide about 24.6 grams of protein, and per ounce they contain roughly 6.9 grams. The math scales predictably: if you eat a larger 4.4-ounce can, you’re looking at closer to 27 grams of protein.
Sardines packed in water tend to have a similar protein count but fewer calories, since you’re not adding fat from olive oil or soybean oil. Sardines in oil run about 208 calories per 100 grams. If you drain the oil thoroughly, you cut some of those calories while keeping nearly all the protein intact. For pure protein-per-calorie efficiency, water-packed sardines have a slight edge.
How Sardines Compare to Tuna and Salmon
Sardines hold their own against other canned fish, though tuna edges ahead on protein alone. In a 3-ounce serving, canned light tuna in oil provides about 24.7 grams of protein compared to sardines’ 21.1 grams. That’s a gap of roughly 3.6 grams per serving.
Where sardines pull ahead is in omega-3 fatty acids. Per 100 grams, sardines deliver about 0.4 grams of EPA and 0.6 grams of DHA, the two omega-3s most linked to heart and brain health. That’s a full gram of combined EPA and DHA per 100-gram serving, which is a strong number for any protein source. Tuna contains omega-3s too, but sardines are consistently among the richest canned sources.
What Else You Get From a Can
Protein is the headliner, but sardines deliver a surprisingly deep nutrient profile for such a small package. Because you eat the bones (they’re soft and barely noticeable), sardines are one of the best non-dairy sources of calcium. They’re also rich in vitamin D and vitamin B12, nutrients that many people fall short on. B12 supports nerve function and energy metabolism, and vitamin D plays a role in bone health and immune function.
The fat content in sardines is worth noting too. A single ounce of sardines canned in oil contains about 3.2 grams of total fat, but most of that fat is unsaturated. Combined with the omega-3s, this makes sardines a nutrient-dense food rather than just a protein source.
Mercury Is Extremely Low in Sardines
One of the biggest advantages sardines have over larger fish is their mercury content. Because sardines are small and low on the food chain, they accumulate very little mercury. FDA testing between 2002 and 2010 found a mean mercury concentration of just 0.013 parts per million in sardines. For context, that’s one of the lowest readings of any commercially available fish. You could eat sardines several times a week without approaching concerning mercury levels, making them a safer choice than swordfish, tuna, or mackerel for people who eat fish regularly.
One Group Should Watch Their Intake
Sardines are high in purines, compounds that break down into uric acid in the body. For most people this is irrelevant, but if you have gout or elevated uric acid levels, sardines can trigger flares. The Mayo Clinic groups sardines alongside anchovies and shellfish as higher-purine seafood. That doesn’t mean you need to avoid them entirely. Small portions eaten occasionally are generally fine, but sardines shouldn’t become a daily staple if gout is a concern for you.
Getting the Most Protein From Your Can
If you’re buying sardines primarily for protein, a few practical details matter. Drain the liquid before eating. Whether it’s oil or water, draining doesn’t remove protein but does reduce excess calories from added fat. Look for cans labeled “in water” or “in olive oil” rather than soybean oil if you care about fat quality. And check the label for added sodium, which varies widely between brands.
Sardines work well mashed on toast, tossed into salads, mixed into pasta, or eaten straight from the can. Because the protein is complete, meaning it contains all nine essential amino acids, sardines are a solid post-workout option or meal component. At roughly 21 to 23 grams of protein per can, two cans a day would cover nearly half the protein needs of an average adult.