Fish Mercury Calculator

Fish and shellfish are an important part of a healthy diet. They are rich in high-quality protein, omega-3 fatty acids, and essential minerals. However, nearly all fish contain trace amounts of mercury. For most people, the health benefits of eating fish outweigh the potential risks. But for certain groups, particularly pregnant women, nursing mothers, and young children, it's important to be mindful of mercury intake. The Fish Mercury Calculator helps estimate your weekly mercury exposure based on the type and amount of fish you consume.

What is Mercury and Why is it in Fish?

Mercury is a naturally occurring element found in the environment. It is released into the air through industrial pollution (like coal-burning power plants) and natural sources (like volcanoes). This mercury falls into oceans and waterways, where bacteria convert it into a more toxic form called methylmercury.

Fish absorb methylmercury from the water and from eating smaller organisms. This substance builds up in their bodies over time, a process called bioaccumulation. Larger, predatory fish that live longer tend to have the highest levels of mercury because they eat many smaller fish, accumulating the mercury from their prey.

How the Calculator Works

This calculator uses data provided by the U.S. Food and Drug Administration (FDA) and the Environmental Protection Agency (EPA) on average mercury concentrations in various types of commercial fish.

• You select the type of fish you've eaten.
• You enter the serving size in ounces or grams.
• The calculator multiplies the serving size by the average mercury concentration for that fish to estimate your total mercury intake for that serving.

It then compares this intake to the weekly reference dose (RfD) established by the EPA. The RfD is an estimate of the maximum daily exposure to a substance that is not expected to cause adverse health effects over a lifetime. The calculator presents your intake as a percentage of this weekly limit.

This calculator is an educational tool to promote awareness about mercury in seafood. It is not a substitute for medical advice. Always consult with your doctor or a registered dietitian for personalized dietary guidance, especially if you are in a high-risk group.