Fish Mercury Calculator

What Is a Fish Mercury Calculator?

Mercury accumulates in fish through a process called bioaccumulation. Larger, longer-lived predatory fish like swordfish, shark, and king mackerel tend to have the highest mercury levels. This calculator estimates your weekly mercury intake from seafood and compares it against EPA safety guidelines based on your body weight.

How Mercury Intake Is Calculated

Fish mercury concentration is given in parts per million (ppm), equivalent to micrograms per gram (µg/g). Mercury per serving in micrograms is:

$$\text{mercury per serving (µg)} = \text{ppm} \times \frac{\text{serving size (g)}}{1000} \times 1000$$

Weekly intake is servings per week multiplied by mercury per serving. The EPA reference dose (RfD) for methylmercury is 0.1 µg per kg of body weight per day. Your weekly safe limit is:

$$\text{weekly limit (µg)} = 0.1 \times \text{body weight (kg)} \times 7$$

The calculator shows what percentage of your safe limit you are consuming and the maximum safe servings per week for your chosen fish.

Mercury Categories

• Low mercury (green): Salmon, shrimp, sardines, tilapia, trout, and most shellfish. Generally safe for regular consumption.
• Moderate mercury (yellow): Tuna (light canned), halibut, snapper, and mahi mahi. Limit portions, especially for pregnant women and children.
• High mercury (red): Swordfish, shark, tilefish, king mackerel, and bigeye tuna. Avoid or eat very rarely.

Pregnant and nursing women, young children, and people with lower body weight have lower safe limits and should be especially careful with moderate and high-mercury fish. For related health calculators, explore tools in the Health & Fitness category.