How much fish should I eat per serving?

January 5, 2026 •

3 min read

The American Heart Association recommends eating two servings of fish, particularly fatty fish, per week [3]. Yet many people are uncertain about proper portion control, asking themselves, "How much fish should I eat per serving?" Determining the right amount ensures you get the heart-healthy benefits of omega-3s without overconsumption.

Quick Summary

A standard fish serving is 3-4 ounces cooked, roughly the size of a deck of cards or the palm of a hand. For optimal health, aim for two servings per week, with one being an oily fish. Recommendations vary for pregnant women and children due to mercury levels, making a variety of low-mercury choices essential for all.

Key Points

Standard Serving Size: A single serving of cooked fish is approximately 3-4 ounces (85-113g), or about the size of a deck of cards or the palm of a hand.
Weekly Recommendations: Aim for at least two servings of fish per week for general health, with at least one serving being a fatty, oily fish like salmon or sardines for a good dose of omega-3s.
Prioritize Low-Mercury Options: To minimize risk, choose low-mercury fish such as salmon, shrimp, tilapia, and canned light tuna for regular consumption.
Adjust for High-Mercury Fish: Limit or avoid high-mercury fish like shark, swordfish, and king mackerel, especially for pregnant women, nursing mothers, and children.
Cooking Method Matters: Opt for healthier cooking methods like baking, grilling, or steaming to maintain the nutritional benefits of the fish and avoid excess fat.

What is a Standard Fish Serving Size?

Determining a standard fish serving size is easier than you might think. A widely accepted guideline is approximately 3 to 4 ounces (85 to 113 grams) of cooked fish [1.2, 2]. This is about the size and thickness of the palm of an average adult's hand or a deck of cards. For uncooked fish, this typically translates to a slightly larger portion, such as 4 to 6 ounces, to account for weight loss during cooking.

The American Heart Association further recommends consuming two servings of fish per week, with a focus on fatty fish rich in omega-3s, such as salmon, mackerel, and herring [3]. Meanwhile, the FDA suggests a minimum of 8 ounces of seafood per week for adults [3].

Why Serving Size Matters

Eating the right amount of fish is a balance of reaping nutritional rewards and mitigating potential risks. Regular consumption offers a host of health benefits, including supporting heart health and providing essential vitamins and minerals [1.2]. However, certain types of fish, particularly those higher on the food chain, can accumulate environmental pollutants like mercury [3]. By adhering to recommended serving sizes, you can maximize the benefits while minimizing exposure to these contaminants.

Fish Serving Recommendations for Specific Populations

Serving recommendations are not one-size-fits-all and should be adjusted for certain individuals, including pregnant women, nursing mothers, and young children, due to developmental concerns related to mercury exposure. For these groups, a variety of low-mercury fish is emphasized, and some high-mercury species should be avoided entirely [3].

Pregnant and Breastfeeding Women: A maximum of 8-12 ounces (2-3 servings) of a variety of low-mercury fish per week is advised. Examples include salmon, shrimp, and tilapia [3]. It's crucial to avoid high-mercury options like shark, swordfish, and king mackerel [3].
Children: The FDA provides age-specific guidelines. For instance, children aged 2 to 4 should have 1-ounce servings, while those aged 4 to 11 can consume 4-ounce servings [3]. Limiting high-mercury fish is especially important for their developing nervous systems [3].

Different Types of Fish and Their Portions

The ideal serving size can also be influenced by the type of fish and its preparation. The following general guidelines can help you portion your meals correctly:

Whole Fish: When cooking a whole fish like sea bass or snapper, aim for approximately one pound (16 ounces) per person to account for the bones and head [2].
Fish Fillets or Steaks: A standard fillet or steak of salmon, tuna, or cod is typically 6-8 ounces for an entrée, while an appetizer portion might be 3-4 ounces [2].
Shellfish: For peeled shrimp or scallops, an entrée portion is about 6-8 ounces, while for shell-on mussels, it might be a pound or more per person [2].

Mercury Levels and Fish Choices

Making informed choices about the type of fish you eat is just as important as the quantity. Fish lower in mercury can be enjoyed more frequently, while high-mercury fish should be consumed sparingly or avoided altogether for vulnerable populations. The FDA and EPA categorize fish based on their mercury content to simplify this process [3, 5].

Best Choices (Low Mercury): Salmon, shrimp, tilapia, cod, sardines, and canned light tuna. These can be consumed 2-3 times per week [3].
Good Choices (Moderate Mercury): Mahi-mahi, albacore tuna, and halibut. Limit consumption to about one serving per week [5].
Avoid (High Mercury): Shark, swordfish, king mackerel, and tilefish. These contain the highest levels of mercury [3].

Comparison of Fish Types by Mercury Level


Fish Type (Example)	Omega-3s	Mercury Level	Recommended Weekly Servings (General Adult)
Salmon (Oily)	High	Low	2-3 servings
Cod (White)	Low	Low	2-3+ servings
Tuna, Albacore (Canned)	Moderate	Moderate	1 serving
Tuna, Canned Light	Low	Low	2-3 servings
Halibut (White)	Moderate	Moderate	1 serving
King Mackerel (Oily)	High	High	Avoid

Conclusion

Understanding how much fish should I eat per serving is fundamental to a balanced diet. By aiming for a standard serving of 3-4 ounces of cooked fish, enjoying two servings per week—including one oily fish—and making informed, low-mercury choices, you can effectively boost your intake of essential nutrients like omega-3 fatty acids. Always remember to adjust portions and fish types based on individual needs, especially for pregnant women and children. This mindful approach ensures a healthy and safe way to enjoy seafood. For more detailed information on specific fish types, the FDA provides comprehensive resources for healthy seafood consumption. [3]

Frequently Asked Questions

Most health organizations, including the American Heart Association and the FDA, recommend eating two servings of fish per week for adults, totaling 8 to 12 ounces [1.2, 3].

A good rule of thumb is that a 4-ounce cooked serving is roughly the size and thickness of the palm of your hand, a checkbook, or a deck of cards [1.2, 2].

Yes, canned and frozen fish are excellent, convenient, and often affordable options. Canned light tuna and salmon are great low-mercury choices. Frozen fish, especially if properly handled, retains its nutritional value [5].

High-mercury fish to limit or avoid include shark, swordfish, king mackerel, and tilefish [3]. It's recommended to choose a variety of low-mercury options for most of your weekly intake.

Yes, serving sizes for children are smaller and age-dependent. For instance, a 2-4-year-old would have a 1-ounce serving, while an 11-year-old would have a 4-ounce serving [3]. It's especially important to focus on low-mercury fish for children.

While the standard serving size is consistent, some guidelines suggest being more mindful of total consumption of oily fish due to higher levels of certain pollutants. For example, some women may need to limit oily fish to two portions per week [3]. White fish can generally be eaten more often.

Yes, pregnant women should be mindful of tuna consumption. While canned light tuna is a low-mercury option, it's generally advised to limit intake to no more than 4 cans or 2 tuna steaks per week [3].