Turn the bottle around. The useful comparison starts with the serving size.
Quick answer: Find the serving size, then the EPA and DHA amounts for that serving. Add those two amounts if you want their combined total. Do not substitute the front-label fish oil weight for that total.
A bottle can display a large number and still leave the important question unanswered: how much of which ingredient are you getting? This walkthrough uses fictional labels so you can practice the calculation without a brand recommendation.
Read the label in this order
First, find “Serving Size.” A serving might be more than one capsule. Second, find EPA. Third, find DHA. Fourth, look for the total oil amount and any separately listed total omega-3 amount. Keep those categories separate.
NIH notes that supplement formulations vary widely. The amount of fish oil does not equal the amount of EPA plus DHA. If the manufacturer does not disclose the amounts you need for a comparison, ask for them rather than estimating from a marketing claim.
Two fictional labels, worked through
| Label detail | Bottle A | Bottle B |
|---|---|---|
| Serving size | 2 capsules | 1 capsule |
| Fish oil per serving | 2,000 mg | 1,000 mg |
| EPA per serving | 360 mg | 400 mg |
| DHA per serving | 240 mg | 200 mg |
| EPA + DHA per serving | 600 mg | 600 mg |
| EPA + DHA per capsule | 300 mg | 600 mg |
Bottle A has the larger total fish oil amount per serving. Both provide the same combined EPA and DHA per serving. Bottle B delivers that amount in one capsule, while Bottle A uses two. Neither calculation establishes which product is right for a particular person.
Use two simple calculations
Combined EPA and DHA per serving = EPA per serving + DHA per serving.
Combined EPA and DHA per capsule = combined amount per serving ÷ capsules per serving.
For Bottle A: 360 + 240 = 600 mg per serving. Divide 600 by two capsules to get 300 mg per capsule. If you take a different number of capsules, you are no longer describing the labeled serving. Do not change an intake to match another bottle without checking the directions and any professional advice you have received.
Keep milligrams and grams straight
One gram equals 1,000 milligrams. In the example, 600 mg is 0.6 g. Record the unit with every number. A comparison sheet that says “600” in one column and “1” in another is not useful until you know what each measures.
“Total omega-3” may include fatty acids beyond EPA and DHA. If that total is larger than EPA plus DHA, do not automatically assume the arithmetic is wrong. Ask what is included. Our EPA and DHA explanation provides the ingredient background.
Check bottle size and price
Imagine Bottle A contains 120 capsules and costs $24. At two capsules per serving, it supplies 60 servings at $0.40 each. If Bottle B contains 60 capsules and costs $30, it supplies 60 servings at $0.50 each. In this example, both bottles contain the same total combined EPA and DHA, but Bottle B costs more and requires fewer capsules per labeled serving.
That is a tradeoff you can describe clearly. It is more informative than comparing bottle price alone. These fictional prices do not represent the current market.
Read beyond the amount column
Check the ingredient source, other ingredients, allergen statements, expiration information, and storage directions. If a product advertises verification, look up what the program assesses. A quality verification mark is not a promise of a clinical outcome.
For the broader buying decision, use our omega-3 supplement buying guide. For source preferences, compare fish, krill, and algae oils.
Questions readers often ask
Can I judge concentration from “triple strength”?
Ask what the product is being compared with. A numerical EPA/DHA disclosure is more useful than a strength adjective without a defined reference.
Does the serving size tell me my personal dose?
It tells you the basis for the label’s quantities. Personal recommendations depend on the reason for use and your health context. This arithmetic exercise is not an instruction to start or increase a supplement.
About the author: Charles Kirkland is the founder of Metabolic Clarity Labs and author of The Journey Back. He is not a physician. This article combines general education with cited sources and is not a medically reviewed treatment plan.
Sources checked October 16, 2026. Educational information only. Do not start, stop, or change a medicine or supplement based on this article. Discuss personal decisions with a qualified clinician or pharmacist.