Calories in Tuna: Nutrition, Portions and Common Serving Sizes

Tuna is a protein-rich food that can vary meaningfully in calories depending on the type of tuna, how it is packed, how thoroughly it is drained and what is added before eating.

That is why there is no single calorie value that accurately describes every tuna product or portion.

If you are tracking calories, the most useful approach is to identify the specific tuna you are eating and estimate the amount that actually reaches your meal.

Calories and nutrition: USDA reference values

Quick answer: 86–90 kcal / 100 g.

The following values describe specific USDA FoodData Central reference foods. They are not universal values for every product.

Calories by edible portion weight

Both references describe canned light tuna in water, drained. Differences between the two datasets are not a universal calorie range for all tuna. Tuna in oil and fresh tuna require separate values.

Sources:

• USDA FoodData Central — SR Legacy, FDC 173709
• USDA FoodData Central — Foundation, FDC 334194

What affects the calories in tuna?

The main factors are:

• whether the tuna is fresh or canned
• whether canned tuna is packed in water, brine or oil
• how much packing liquid remains after draining
• the species and cut
• the portion size
• added oil, mayonnaise, sauces or other ingredients
• the nutrition information for the specific product

These differences can matter more than trying to memorize one generic number.

Tuna in water or brine

Tuna packed in water or brine is generally relatively lean because the packing liquid contributes little or no fat.

Once drained, most of the energy comes from the tuna itself.

However, products can still differ.

The most reliable value for packaged tuna is usually the nutrition information on the product you actually bought.

Tuna in oil

Oil-packed tuna can contain more calories because some oil remains with the fish.

Draining the can can remove part of the oil, but it does not necessarily remove all of it.

The amount remaining depends on:

• the product
• the type of oil
• how the tuna is packed
• how long and how thoroughly it is drained

This is why simply treating every drained oil-packed tuna as equivalent to water-packed tuna can underestimate intake.

Does draining tuna change the calories?

It can.

With tuna packed in water or brine, draining mainly changes the amount of liquid and therefore the weight.

With oil-packed tuna, draining can also remove some dietary fat and energy.

The important question is what the nutrition label refers to.

Depending on the product and market, nutrition information may refer to the food as sold or to a drained portion.

Read the label carefully rather than assuming.

Net weight and drained weight are different

A can can contain both tuna and packing liquid.

The total package weight is therefore not necessarily the amount of tuna you eat.

For calorie tracking, the drained amount can be more relevant when the liquid is discarded.

If the oil or liquid is used in the meal, it should not automatically be ignored.

How to estimate your tuna portion

If you eat the entire drained contents of a can, tracking can be relatively straightforward when the product provides suitable nutrition information.

If you eat only part of it, you can:

1. drain the tuna in the way you normally would
2. determine the amount you actually use
3. use the nutrition information that corresponds to that product
4. save or refrigerate the remainder safely

You do not need to force every serving into a standard portion size.

Track the amount you actually eat.

Common tuna portion situations

The entire small can

If you use all of the drained tuna, use the relevant product information for the full amount you consumed.

Half of a larger can

Do not automatically log a generic “one serving.”

Estimate the fraction or weight you actually used.

Tuna shared between two meals

If one package is divided between lunch and dinner, the total can be allocated between the two meals according to the amount used.

Tuna added to a mixed dish

For pasta, salad, wraps or casseroles, count the tuna as one ingredient within the complete recipe.

Fresh tuna is different from canned tuna

Fresh tuna steaks are not nutritionally identical to every canned tuna product.

Calories and fat can vary with species, cut and preparation.

Cooking oil can also materially change the final energy content.

If you are tracking fresh tuna, use data that matches the specific type and preparation as closely as practical.

Cooking method matters

Tuna cooked without much added fat will differ from tuna cooked with:

• olive oil
• butter
• creamy sauce
• glaze
• marinade containing substantial oil or sugar

The tuna itself may be relatively straightforward to estimate, while the cooking additions can create the larger tracking difference.

Tuna and protein

Tuna is commonly used as a concentrated source of protein.

That can make it useful in meals where you want to increase protein without adding a very large food volume.

Your total protein requirement, however, depends on the individual and the overall diet.

See How Much Protein Do You Need Per Day?.

Tuna and dietary fat

Water-packed tuna is often relatively low in fat, while oil-packed tuna can contribute more fat depending on how much oil remains.

Neither format is automatically “better.”

The useful choice depends on:

• taste
• meal composition
• total diet
• calorie needs
• convenience

If the meal is otherwise very low in fat, oil-packed tuna may fit easily.

If the meal already contains mayonnaise, avocado, cheese or a substantial dressing, water-packed tuna may make the total easier to adjust.

Tuna in a balanced meal

Tuna does not need to be eaten alone.

It can be combined with:

• potatoes
• rice
• pasta
• bread
• beans
• vegetables
• salad ingredients
• yogurt-based sauces
• olive oil
• herbs and spices

The calories in the complete meal depend on all of these ingredients, not only the tuna.

Tuna salad calories can vary widely

The phrase “tuna salad” can describe very different foods.

One version may contain tuna, vegetables and a yogurt-based dressing.

Another may contain substantial mayonnaise, oil, cheese or other energy-dense ingredients.

Therefore, a generic calorie value for “tuna salad” can be inaccurate for the meal in front of you.

When possible, track the major ingredients separately.

Tuna sandwiches and wraps

For sandwiches and wraps, remember to include:

• bread or tortilla
• tuna
• mayonnaise or sauce
• cheese
• avocado
• oil-based dressing
• other substantial additions

Vegetables may contribute relatively little energy, but they are still part of the meal.

The largest differences often come from the bread, sauces, cheese and added fats.

Tuna pasta

In a tuna pasta dish, pasta and added fats may contribute a substantial share of total calories.

A useful estimate includes:

• dry or cooked pasta amount
• tuna
• cooking oil
• sauce
• cheese
• other significant ingredients

Avoid assigning the entire dish a generic value based only on the presence of tuna.

Tuna with mayonnaise

Mayonnaise can substantially increase the energy density of a tuna mixture.

If calorie accuracy matters to you, estimate the amount of mayonnaise rather than treating “tuna with mayo” as a standard food with one fixed value.

The same principle applies to other creamy or oil-based sauces.

What if you cannot weigh the tuna?

You can still make a practical estimate.

Useful information includes:

• package size
• drained weight if available
• the fraction of the package eaten
• whether the tuna was packed in water or oil
• how much liquid remained
• whether other ingredients were added

A reasonable estimate based on the actual product is generally more useful than choosing an unrelated generic serving.

Photo-based tracking and tuna

Tuna can be difficult to estimate from a photo when it is mixed with other ingredients.

A photo may not reveal:

• whether the tuna was packed in oil
• how much mayonnaise is mixed in
• how much tuna is hidden beneath other foods
• whether extra oil was added
• the exact portion weight

Photo recognition can provide a starting point, but additional information can improve the estimate.

See Can AI Estimate Portion Size From a Photo?.

Correcting an estimate

If an AI estimate identifies tuna correctly but the amount or preparation is wrong, you do not need to replace the entire food log.

Correct the information that matters.

For example:

• change water-packed to oil-packed tuna
• adjust the amount
• add mayonnaise
• add cooking oil
• correct the portion of the can eaten

See How to Correct an AI Food Estimate.

Should you track the oil from canned tuna?

If you discard most of the oil, the amount you consume may be lower than the total oil originally in the package.

If you deliberately use the oil in the meal, it becomes part of what you eat and should be considered when estimating the meal.

The product label and the way you actually use the food are both relevant.

What about tuna in spring water?

From a calorie-tracking perspective, tuna packed in spring water is generally handled similarly to other water-packed tuna.

Still, use the product-specific nutrition information when available.

Does tuna contain carbohydrates?

Plain tuna contains little to no carbohydrate.

Carbohydrates in a tuna-based meal usually come from other ingredients such as:

• bread
• pasta
• rice
• potatoes
• wraps
• sauces containing sugar or starch

Is tuna good for weight loss?

No single food causes weight loss.

Tuna can fit into a weight-loss diet because it can provide substantial protein and, depending on the product, relatively modest energy.

But the full meal still matters.

A tuna dish containing large amounts of mayonnaise, oil or other energy-dense additions can have a very different calorie content from plain drained tuna.

For a broader approach, see How to Build a Filling Meal for Weight Loss.

Food safety matters

Canned tuna should be stored according to the product instructions.

After opening, unused tuna should be transferred or covered appropriately, refrigerated promptly and used within a safe period according to applicable food-safety guidance.

Fresh tuna requires appropriate refrigeration and cooking or handling practices.

Tuna consumption and mercury

Tuna species can differ in mercury content.

Recommendations on tuna consumption can vary by species, product type, country, age, pregnancy status and other individual circumstances.

If this is relevant to you, follow current guidance from the appropriate food-safety or health authority in your country rather than relying on a generic serving rule.

A practical tracking workflow

1. Identify the product

Fresh, water-packed, brine-packed or oil-packed?

2. Check what the nutrition information refers to

Look at whether the values correspond to the product as sold or drained where applicable.

3. Determine how much you actually eat

Whole package, part of a package or an amount used in a recipe?

4. Account for oil or sauce

Especially when it is consumed rather than discarded.

5. Add the other meal ingredients

Bread, pasta, mayonnaise, cheese and oils can materially change the total.

6. Correct estimates when necessary

If a photo or database entry does not match the actual tuna, adjust the relevant detail.

Common tracking mistakes

Logging every tuna product as identical

Water-packed and oil-packed products can differ.

Using total can weight when the liquid is discarded

The amount actually eaten may be different.

Assuming draining removes all oil

Some oil can remain with the tuna.

Forgetting mayonnaise

This can meaningfully change the energy content of a tuna mixture.

Ignoring cooking oil with fresh tuna

Added fat is part of the meal.

Using a generic portion instead of the amount eaten

Your actual portion matters more than an arbitrary serving.

Tracking only the tuna in a mixed meal

Bread, pasta, sauces, cheese and other ingredients also contribute to the total.

Frequently asked questions

Is tuna high in calories?

Plain tuna can be relatively lean, especially when packed in water, but calorie content varies with the product, packing medium and preparation.

Does tuna in oil have more calories than tuna in water?

It often can because oil contributes additional energy. The actual difference depends on the product and how much oil remains after draining.

Does draining tuna remove calories?

Draining oil-packed tuna can remove some oil and therefore some energy. The amount removed varies.

Should I use net weight or drained weight?

If the packing liquid is discarded, drained weight may better represent the tuna actually eaten. Always check what the nutrition information on the product refers to.

Is fresh tuna the same as canned tuna?

No. Species, cut, processing, packing medium and preparation can all affect the nutrition profile.

Can I estimate tuna from a photo?

A photo can help identify the food, but it may not reveal packing oil, mayonnaise, hidden ingredients or exact portion size.

Is tuna a good protein source?

Tuna is commonly a protein-rich food, although the exact amount depends on the product and portion.

Do I need to weigh tuna every time?

Not necessarily. Package information and the fraction consumed can often provide a practical estimate. Weighing can be useful when greater precision matters.

The bottom line

Calories in tuna depend on more than the word “tuna.”

For a useful estimate, consider:

• the specific tuna product
• water, brine or oil packing
• whether and how it was drained
• the amount actually eaten
• added oils and sauces
• the other ingredients in the meal

Use the product-specific nutrition information when available and track the portion you actually consume.

For mixed dishes, focus on the ingredients that meaningfully affect the total rather than relying on one generic tuna value.

This article provides general educational nutrition information and is not individualized medical or dietary advice.