Fish Mercury Calculator
This fish mercury calculator help you make informed decisions about seafood intake by calculating potential mercury levels based on fish species, portion size, and consumption frequency.
The calculator particularly benefits pregnant women, nursing mothers, and young children who need to monitor their mercury intake closely.
If someone consumes 6 ounces of tuna twice weekly, the calculator would assess their mercury exposure by multiplying the mercury concentration in tuna (approximately 0.391 ppm) by the consumption amount and frequency.
Mercury Levels in Fish Chart
| Fish | Mercury Level (ppm) | Recommendation |
|---|---|---|
| Low Mercury | ||
| Salmon | 0.01 – 0.05 | Safe to eat 2-3 servings per week |
| Sardines | 0.01 – 0.02 | Safe to eat 2-3 servings per week |
| Tilapia | 0.01 – 0.07 | Safe to eat 2-3 servings per week |
| Shrimp | 0.01 | Safe to eat 2-3 servings per week |
| Moderate Mercury | ||
| Tuna (canned light) | 0.12 | Limit to 1 serving per week |
| Cod | 0.11 | Limit to 1 serving per week |
| Mahi-mahi | 0.19 | Limit to 1 serving per week |
| High Mercury | ||
| Swordfish | 0.97 | Avoid or eat rarely |
| Shark | 0.98 | Avoid or eat rarely |
| King Mackerel | 0.73 | Avoid or eat rarely |
| Bigeye Tuna | 0.68 | Avoid or eat rarely |
Fish Mercury Calculation Formula
The formula for calculating mercury exposure from fish is:
Mercury Exposure = (Fish Weight in grams × Mercury Concentration in ppm × Number of servings per week) ÷ Body Weight in kilogramsMercury per Serving = Fish Mercury Level × (Fish Weight in kg)Weekly Mercury Intake = Mercury per Serving × Weekly ConsumptionDaily Mercury Intake = Weekly Mercury Intake ÷ 7Relative Exposure = (Daily Mercury Intake ÷ (Body Weight × EPA Limit)) × 100A 70kg person eating 170g (6 oz) of tuna (0.391 ppm) twice weekly:
(170g × 0.391 ppm × 2) ÷ 70kg = 1.89 μg/kg/weekMercury per Serving (mg) = Mercury Level (mg/kg) × Fish Weight (kg)Weekly Mercury (mg) = Mercury per Serving (mg) × Consumption Frequency (per week)- Mercury Level (mg/kg): Mercury concentration for the selected fish species.
- Fish Weight (kg): The weight of fish consumed in kilograms (converted from grams).
How to Know How Much Mercury is in Fish?
- Select the Fish Species: Choose the fish type you consume from the dropdown list. Each fish type has an associated mercury concentration value (mg/kg).
- Enter the Weight of Fish Consumed Per Serving: Input the weight of fish (in grams) you typically eat in one meal.
- Enter Your Body Weight: Provide your body weight (in kilograms), as mercury safety limits are weight-dependent.
- Enter Frequency of Consumption: Specify how many times per week you consume the selected fish.
Larger predatory fish like swordfish typically contain higher mercury levels (around 0.995 ppm) compared to smaller fish like sardines (0.013 ppm).
- Salmon (0.022 ppm): 150g serving × 0.022 ppm × 3 times/week ÷ 65kg = 0.015 μg/kg/week
- Shark (0.979 ppm): 200g serving × 0.979 ppm × 1 time/week ÷ 70kg = 2.80 μg/kg/week
- Light Tuna (0.126 ppm): 100g serving × 0.126 ppm × 4 times/week ÷ 60kg = 0.084 μg/kg/week
- Swordfish (0.995 ppm): 180g serving × 0.995 ppm × 1 time/week ÷ 75kg = 2.39 μg/kg/week
- Cod (0.111 ppm): 130g serving × 0.111 ppm × 2 times/week ÷ 80kg = 0.036 μg/kg/week
What is Fish Mercury?
Fish mercury refers to methylmercury, an organic form of mercury that bioaccumulates in aquatic food chains. This toxin enters waterways through natural and anthropogenic sources, including volcanic activity, industrial emissions, and mining operations. Fish absorb mercury primarily through their diet, with concentrations increasing up the food chain through bioaccumulation.