One 5-oz can of light tuna has about 14 µg of mercury; a same-size albacore can holds around 40 µg.
Mercury in canned tuna varies by species. The small, fast-growing fish used for most “light” cans sit on the low end, while white tuna pulls more. Below you’ll see the typical amounts per can, how those figures are calculated from government data, and simple ways to choose servings with confidence.
How Much Mercury Per Can Of Tuna: Typical Amounts
To translate lab results into numbers you can use, start with the average mercury concentration for each tuna category and multiply by the edible fish in a standard can. The averages come from long-running federal monitoring. A 5-oz can yields roughly a single palm-size portion once drained, so the math lines up with common serving sizes.
Method At A Glance
- Concentrations: Mean mercury levels (ppm) by tuna category from the FDA’s commercial seafood database.
- Portion used: One drained 5-oz can (about 113 g fish) for the per-can estimates; a 4-oz (113 g) serving for per-serving figures when noted.
- Conversion: ppm equals micrograms per gram (µg/g). Multiply ppm by grams of fish to get total µg mercury.
Estimated Mercury Per Standard Can
Assumes one drained 5-oz can ≈ 113 g edible fish; actual label weights vary by brand and pack style.
| Tuna Type | Mean Mercury (ppm) | Estimated Mercury Per 5-oz Can (µg) |
|---|---|---|
| “Light” (mostly skipjack) | 0.126 | ~14 |
| White (albacore), canned | 0.350 | ~40 |
| Yellowfin, canned or chunk | ~0.35 (category average varies) | ~40 |
Those ranges reflect averages. Individual cans can test lower or higher, since fish size, region, and diet shift the numbers.
Where These Numbers Come From
The FDA runs an ongoing monitoring program and publishes mean mercury levels for commercial seafood. In that dataset, canned light tuna averages 0.126 ppm, while canned white tuna averages 0.350 ppm. Multiply by a single 5-oz can (about 113 g drained) and you land near 14 µg and 40 µg, respectively. You can review the full seafood table on the FDA site; it lists tuna alongside dozens of other species with the same measurement method.
Quick Comparison To A Single Serving
Federal meal guidance uses a 4-oz adult portion. Using the same concentrations, that 4-oz serving of canned light tuna lands near 14 µg, and a 4-oz serving of white tuna lands near 40 µg. Since a drained can is roughly a single portion, the serving-based view matches the per-can math.
What Affects Mercury In Canned Tuna
Species Matters
Skipjack grows quickly and sits low in the marine food chain, so its cans stay lower. Albacore and yellowfin grow larger and live longer, so they carry more.
Fish Size And Age
Within the same species, bigger and older fish tend to contain more mercury. That’s why averages work for menu planning, but any single lot can land above or below the mean.
Catch Area And Pack Style
Ocean region and diet influence results. Packing in water or oil doesn’t change mercury in the fish itself; mercury binds to the muscle tissue, not the liquid.
How Many Cans Fit Normal Advice
Consumer guidance groups canned fish by mercury level and set simple weekly patterns. Canned light tuna sits in the low-mercury “Best Choices” group, while albacore and yellowfin sit in the “Good Choices” group with a lower weekly frequency. The aim is to keep average intake in a safe range while still getting the nutrition benefits from fish.
See the joint EPA-FDA fish advice for the full chart of “Best Choices,” “Good Choices,” and “Choices to Avoid,” plus serving sizes by age. The advice also clarifies how many servings to eat in a typical week and how to mix types for variety. EPA-FDA fish advice
Simple Weekly Patterns
- Adults: Two to three 4-oz portions from the low-mercury list each week, or one portion from the “Good Choices” list.
- Pregnant or breastfeeding: The same pattern, leaning on low-mercury picks; variety is the goal.
- Kids: Two portions from the low-mercury list, but smaller sizes by age (1–3 yrs: ~1 oz; 4–7 yrs: ~2 oz; 8–10 yrs: ~3 oz; 11+ yrs: ~4 oz).
How To Decide Between Light And White
Pick canned light when you want a tuna sandwich or salad in your regular rotation. Pull white tuna when you want a firmer texture or milder flavor and keep it to a once-weekly slot. That simple swap keeps intake steady without micromanaging math.
Label Clues That Help
- “Light” or “Chunk Light” usually means skipjack or a mix with smaller species.
- “White” means albacore.
- Drain well before weighing or portioning; the fish, not the liquid, carries mercury.
How We Calculate Per-Can Mercury
Here’s the math you can apply to any can in your pantry if the label lists drained weight:
- Find the average mercury for your tuna type (ppm).
- Convert ppm to µg/g (same number).
- Multiply by grams of drained fish in the can.
Example: Canned light tuna at 0.126 ppm × 113 g ≈ 14.3 µg in the can. White tuna at 0.350 ppm × 113 g ≈ 39.6 µg.
What Those Micrograms Mean
EPA’s reference dose for methylmercury is 0.1 µg per kilogram of body weight per day. That benchmark shaped the serving guidance above. You don’t need to live on a calculator; sticking to the weekly patterns keeps you in line with that safety margin.
If you want the technical background behind that benchmark, EPA explains the reference dose and how it’s derived from long-term studies. EPA methylmercury reference dose
Serving Ideas That Fit The Guidance
Rotate low-mercury picks through the week. A quick tuna salad made with chunk light works on a weekday. On another day, try salmon, sardines, or trout for variety. If you enjoy albacore, save it for one lunch that week and choose low-mercury fish for the rest.
Portion Sizes By Age And Goal
Adults can think in 4-oz blocks. Teens can match that by age 11+. Younger kids step up gradually. If you eat more fish in one week, tilt toward low-mercury choices the next week to keep averages level.
| Who | Light Tuna (weekly) | White Tuna (weekly) |
|---|---|---|
| Adults | 2–3 × 4-oz portions | 1 × 4-oz portion |
| Pregnant/Breastfeeding | 2–3 × 4-oz portions | 1 × 4-oz portion |
| Kids (1–3 yrs) | 2 × ~1-oz portions | Skip or keep rare |
| Kids (4–7 yrs) | 2 × ~2-oz portions | Skip or keep rare |
| Kids (8–10 yrs) | 2 × ~3-oz portions | Skip or keep rare |
| Kids (11+ yrs) | 2 × 4-oz portions | 1 × 4-oz portion |
Answers To Common Reader Needs
Is One Sandwich A Day Ok?
If that sandwich uses chunk light, you can fit several across the week by mixing in other low-mercury fish. If you prefer albacore, space it out and fill the rest of the week with shrimp, salmon, or sardines.
Does Rinsing Reduce Mercury?
No. Mercury sits in the muscle tissue. Draining or rinsing helps with sodium and flavor; it doesn’t change mercury in a meaningful way.
Oil-Pack Or Water-Pack?
Pick the texture you like. Pack liquid choice doesn’t affect mercury. Check the label if you’re watching sodium or calories.
A Quick Checklist For The Grocery Aisle
- Choose light for routine meals; save white tuna for an occasional swap.
- Scan for species on the label. Skipjack aligns with lower mercury.
- Portion smart: think in 4-oz servings for adults; smaller for kids.
- Plan variety: add salmon, sardines, trout, shrimp, or pollock on other days.
Key Takeaways You Can Use Today
- A typical 5-oz can of chunk light carries around 14 µg of mercury on average.
- A same-size can of white tuna lands near 40 µg.
- Follow the simple weekly pattern: light tuna two to three times; white tuna once.
- Mix in other low-mercury seafood to keep variety high and intake steady.
Sources And Data Notes
Mercury concentrations for canned tuna come from the FDA’s public seafood table, which aggregates thousands of samples over many years. You can scan that table here: FDA mercury levels in seafood. Serving patterns and age-based portions come from the joint federal advice here: EPA-FDA advice about eating fish. EPA’s background on the methylmercury reference dose is explained here: EPA methylmercury reference dose.