Fish Mercury Calculator
Check mercury levels in fish with our free calculator. Enter fish type, serving size, and body weight to see your weekly mercury intake vs EPA safe limits.
About This Calculator
About Mercury in Fish
Methylmercury is a neurotoxin that accumulates in fish through the food chain. Larger, predatory fish at the top of the food chain (shark, swordfish, king mackerel, tilefish) have the highest concentrations. The calculator uses the EPA reference dose of 0.1 µg/kg/day and the EPA/FDA mercury database to help you make informed choices about seafood consumption.
Fish Classification by Mercury Level
Low Mercury (<0.1 ppm): Sardines, tilapia, anchovies, salmon, catfish, pollock, shrimp. These are the "Best Choices" -- eat 2-3 servings per week.
Moderate Mercury (0.1-0.5 ppm): Cod, canned light tuna, snapper, mahi-mahi, halibut, canned albacore tuna, Chilean sea bass. These are "Good Choices" -- limit to 1 serving per week.
High Mercury (0.5-1.0 ppm): Orange roughy, Spanish mackerel, grouper, bluefin tuna, king mackerel. "Eat Less Often" -- occasional consumption only.
Avoid (>1.0 ppm): Tilefish (Gulf of Mexico), shark, swordfish. These have the highest mercury levels and should be avoided, especially during pregnancy.
Regional Advisory Bodies
India: The Food Safety and Standards Authority of India (FSSAI) and ICAR monitor mercury in seafood. Common low-mercury fish include Indian mackerel (bangda), sardines (tarli/mathi), and freshwater fish like rohu and tilapia. Avoid large predatory fish like shark (saur) and king mackerel (surmai).
United States: The FDA and EPA jointly issue the "Advice About Eating Fish" with the "Best Choices," "Good Choices," and "Choices to Avoid" categories. Women who are pregnant or breastfeeding and children should follow these guidelines closely.
United Kingdom: The Food Standards Agency (FSA) recommends 2 portions of fish per week (one oily, one white). Limit oily fish to 4 portions per week and avoid eating shark, swordfish, or marlin more than once a week. Pregnant women and those trying to conceive should avoid these entirely.
Frequently Asked Questions About Mercury in Fish
What mercury level in fish is considered safe?
The EPA sets a reference dose (RfD) of 0.1 micrograms of methylmercury per kilogram of body weight per day. Fish with mercury levels below 0.1 ppm (e.g. salmon, sardines, tilapia) are considered low-risk and can be eaten 2-3 times per week. Levels above 1.0 ppm (e.g. shark, swordfish, tilefish) should be avoided entirely, especially by pregnant women and children.
Which fish have the highest mercury levels?
King mackerel, shark, swordfish, and tilefish from the Gulf of Mexico have the highest mercury levels, often exceeding 0.9 ppm. Bigeye tuna and orange roughy are also high at 0.5-0.7 ppm. These predatory fish accumulate mercury through biomagnification as they feed on smaller fish over their long lifespans.
How does the Fish Mercury Calculator work?
Select a fish type to get its mercury content from the EPA/FDA database. Enter the serving size in grams, weekly servings, and your body weight. The calculator multiplies mercury concentration (ppm) by serving size to estimate total mercury intake per serving and per week, then compares it against the EPA reference dose to assess safety.
How much fish can I safely eat each week?
The FDA and EPA advise 2-3 servings (8-12 oz total) per week of low-mercury fish like salmon, sardines, and tilapia. For moderate-mercury fish like halibut or canned albacore tuna, limit to 1 serving per week. Pregnant women, nursing mothers, and young children should avoid high-mercury fish entirely and stick to the 'Best Choices' list.
Do fish consumption advisories differ between India, the US, and the UK?
Yes. In India, the FSSAI and ICAR advise limiting large predatory fish like shark (saur) and king mackerel (surmai) due to mercury concerns; common Indian fish like sardines (mathi), mackerel (bangda), and tilapia are low in mercury. The US FDA/EPA provide the 'Best Choices', 'Good Choices', and 'Avoid' lists. The UK FSA recommends 2 portions of fish per week, one being oily fish, but warns against eating more than 4 portions of oily fish or 2 portions of shark/ swordfish/ marlin per week.
What are the symptoms of mercury poisoning from fish?
Chronic methylmercury exposure can cause numbness or tingling in extremities, muscle weakness, coordination problems, vision and hearing impairment, and memory issues. Severe poisoning may affect speech and walking. At-risk groups -- pregnant women and children -- face developmental delays and cognitive deficits. If you experience symptoms, consult a doctor and reduce high-mercury fish intake.
How accurate are the mercury values used in this calculator?
Mercury concentrations are sourced from the FDA's 1990-2012 monitoring database and the EPA's fish tissue studies. Levels vary by location, fish size, and season. The values are population averages and serve as a general guideline. For the most precise assessment, consult your local health authority's fish advisory for your specific water body.
Does cooking fish reduce mercury content?
No. Methylmercury is bound to fish protein and is not destroyed by cooking, grilling, frying, or freezing. The mercury content in cooked fish remains essentially the same as raw fish, though weight loss from moisture evaporation can slightly concentrate it. The only way to reduce mercury risk is to choose lower-mercury fish species.