In canned tuna, one 5-oz can of light tuna averages ~14 µg mercury; white (albacore) averages ~40 µg based on FDA testing.
Shoppers reach for canned tuna because it’s lean, handy, and budget-friendly. The question everyone asks is about mercury. You’ll see different numbers online, so let’s ground it in lab data and do the math step by step. Below, you’ll find clear ranges, quick conversions for a typical can, and smart ways to keep tuna in the meal plan without overdoing exposure.
What “Mercury In Canned Tuna” Really Means
Mercury measurements for seafood are usually listed as parts per million (ppm). One ppm equals one microgram per gram (µg/g). Canned tuna is sold mostly as “light” (often skipjack) and “white” (albacore). FDA monitoring shows a higher average for albacore than for light tuna. We’ll use those official means and convert them into micrograms per common serving and per full can, so you can size up your intake with real numbers from a trusted program. (Source: FDA fish monitoring table.)
Mercury Numbers At A Glance (Per Serving And Per Can)
To keep numbers consistent, this table uses two practical portions:
- Label serving often shown on cans: ~2 oz (56 g) drained.
- Typical full 5-oz can, drained solids: ~4 oz (113 g).
Calculations use FDA mean mercury values: light tuna ~0.128 ppm; albacore ~0.350 ppm. Multiplying ppm by grams gives micrograms (µg). (Source: FDA data.)
| Tuna Style | Mean Mercury (ppm) | Mercury Per Portion (µg) |
|---|---|---|
| Light (Skipjack/“Chunk Light”) | 0.128 |
~7 µg per 2 oz (56 g) ~14 µg per 5-oz can drained (~113 g) |
| White (Albacore) | 0.350 |
~20 µg per 2 oz (56 g) ~40 µg per 5-oz can drained (~113 g) |
Close Variant: How Much Mercury Is In A Tuna Can Serving? Practical Math
Here’s the quick method you can reuse for any brand: take the mercury value in ppm and multiply by the drained grams you plan to eat. Example with light tuna: 0.128 × 113 g ≈ 14 µg for a full 5-oz can. Do the same with albacore: 0.350 × 113 g ≈ 40 µg. These numbers sit far below the FDA action level for seafood (1.0 ppm), which is the threshold that can trigger enforcement. (See FDA mercury levels and the 1.0 ppm action level.)
Serving Sizes And Why Your Label Might Differ
Labels follow federal serving rules known as RACCs (reference amounts). For fish, federal advice often frames a serving as 4 oz (113 g) edible portion. That’s the baseline many health advisories use. Canned products may also show a 2-oz drained serving on the panel for everyday tracking. If you eat a whole standard can, you’ve eaten close to the 4-oz drained amount. (Source: EPA-FDA fish advice technical notes.)
How Much Is Safe Per Week For Most Adults?
The U.S. EPA set a reference dose for methylmercury: 0.1 µg per kilogram of body weight per day. Think of it as a steady weekly budget. For a 70-kg adult, that’s about 7 µg/day, or ~49 µg in a week. Compare that to the table above and you’ll see why many people comfortably fit a can of light tuna into a week, and why albacore servings call for a bit more planning. (Sources: EPA IRIS summary and supporting documents.)
Special Guidance For Pregnancy And Young Children
During pregnancy and early childhood, seafood brings protein and omega-3s, but choosing lower-mercury species matters. The joint federal advice groups species into “Best Choices,” “Good Choices,” and “Choices To Avoid.” Light tuna falls into the lower-mercury camp; albacore sits higher. Always follow the serving guidance that applies to your situation. You can check the federal list by species and serving frequency here: EPA-FDA fish advice.
Brand-To-Brand Swings And Why Averages Help
Mercury varies with species, catch area, and fish size. Averages from large monitoring sets smooth out spikes and dips. That’s why the FDA table is handy for planning: it reports thousands of samples across years. If you rotate tuna with other low-mercury fish such as salmon, cod, pollock, or shrimp, your overall exposure stays modest while you still get seafood’s benefits. (Source: FDA monitoring program.)
Choosing Between Light And Albacore
Pick light tuna when you want more frequent tuna meals with lower mercury. Choose albacore for a firmer texture and stronger flavor, but plan fewer servings. Oil-packed or water-packed doesn’t change mercury much, since mercury lives in the muscle. Draining the can changes weight, not the concentration. The species choice is the lever that matters most for exposure. (Source: FDA data set.)
How These Numbers Compare With The Action Level
People sometimes confuse personal intake with the FDA action level. The action level (1.0 ppm methylmercury in fish) is a regulatory trigger for products on the market, not a personal intake target. The values for light and albacore canned tuna sit well under that line on average. Your intake calculation is separate: ppm × grams eaten gives your micrograms for the day or week. (Source: FDA action level appendix.)
Simple Ways To Keep Intake In Check
- Alternate styles: use light tuna for most meals; save albacore for a recipe that needs its texture.
- Rotate species: mix in salmon, sardines, shrimp, or cod to spread exposure across low-mercury picks.
- Track portions: half a standard can (~2 oz drained) keeps mercury low while still adding protein.
- Mind kids’ portions: smaller bodies mean smaller weekly budgets; follow the federal chart linked above.
Math You Can Use For Any Can
Got a can that lists a different drained weight? Just multiply the FDA mean by the grams you’ll eat. If your can lists 85 g per serving of albacore, that’s 0.350 × 85 ≈ 30 µg. If the label shows 56 g, 0.350 × 56 ≈ 20 µg. With light tuna, the same math comes out to smaller numbers. Keep a quick note on your phone and you can tally a week in seconds. (Source: FDA monitoring table.)
Weekly Budgets Based On Body Weight
The table below converts the EPA reference dose into weekly “microgram budgets,” then shows how many 2-oz drained servings fit for each tuna style. These are planning numbers, not medical advice.
| Body Weight | Light Tuna Servings/Week (~7 µg per 2 oz) |
Albacore Servings/Week (~20 µg per 2 oz) |
|---|---|---|
| 50 kg (110 lb) | Up to ~7 servings | Up to ~2 servings |
| 70 kg (154 lb) | Up to ~9 servings | Up to ~2 servings |
| 90 kg (198 lb) | Up to ~12 servings | Up to ~3 servings |
How these rows were made: weekly budget = 0.1 µg × body-weight × 7 days. Then divide by the mercury per serving. A 70-kg adult has ~49 µg to “spend” in a week. With light tuna at ~7 µg per 2 oz, that’s about nine small servings; with albacore at ~20 µg per 2 oz, that’s about two. (Sources: EPA reference dose; FDA means.)
When You Want More Detail
Want to compare beyond tuna? The FDA table lists dozens of species with their mean and range. It’s handy when you plan meals for pregnancy or for kids. You’ll also find the joint federal consumer page that groups fish into “Best,” “Good,” and “Avoid” choices with recommended servings. Bookmark both pages for quick checks while shopping. (FDA mercury table; EPA-FDA fish advice.)
Quick Answers To Everyday Situations
Meal Prep With Multiple Cans
Making a big salad with two cans of light tuna? That’s ~28 µg across the batch using the 14 µg per can estimate. Split into four lunches and you’re near ~7 µg per serving. Swap in one can of albacore and one can of light, and the batch rises to ~54 µg; divide it into four and you’re near ~14 µg per serving. Use the same math for pasta bakes, melts, and wraps. (Source: FDA means.)
Switching Between Pouch And Can
Pouches often list a 2.5-oz drained serving. Multiply by the same ppm. A light tuna pouch at 71 g comes out to ~9 µg (0.128 × 71). An albacore pouch hits ~25 µg (0.350 × 71). The container type doesn’t change the ppm; the portion size does. (Source: FDA monitoring.)
What About “Low Mercury” Claims?
Claims aside, the sure way to plan is to use the species average and your grams eaten. The FDA action level is a market-enforcement line at 1.0 ppm, not a label for personal safety at the plate. Using the averages keeps your weekly math steady, brand to brand. (Source: FDA action level appendix and monitoring table.)
Bottom Line For Canned Tuna Lovers
Most pantry-style tuna meals land well below federal enforcement thresholds, and the averages let you plan with confidence. Pick light tuna for frequent meals, save albacore for a recipe that needs it, and keep an eye on weekly totals if you’re cooking for pregnancy or kids. For a one-can day, think ~14 µg with light tuna and ~40 µg with albacore. Bookmark the official pages linked above for quick checks any time you want to confirm a number. (Sources: FDA monitoring; EPA-FDA advice; EPA IRIS.)