This omega-3 dosage calculator answers one narrow question: given the EPA and DHA figures printed on a fish-oil label and the number of capsules taken, how many milligrams of long-chain omega-3 does that actually amount to in a day? It then shows that total against a reference figure you type in yourself. It does not recommend an intake, does not tell you whether your current intake is high or low, and returns no verdict of any kind.
That restraint is the point. Arb Digital builds free calculators that do the arithmetic honestly and stop where the evidence stops. Fish-oil intake is not a neutral arithmetic problem — it interacts with bleeding risk and with anticoagulant and antiplatelet medicines, the published reference figures differ between national authorities, and in many countries supplements are not regulated the way medicines are. A page that handed out a number in milligrams would be pretending to a certainty that the underlying guidance does not have.
What This Omega-3 Calculator Does
It multiplies the EPA and DHA content of one capsule by the number of capsules taken per day, adds the two together, and reports the combined total. Alongside that it shows EPA and DHA separately, because many products are heavily weighted towards one of them, and it shows the combined total as a share of whatever reference figure you entered. If you also give the total oil per capsule, it shows what percentage of that oil is actually EPA and DHA — usually the most surprising number on the page.
Everything it reports is derived from figures you supplied. It holds no internal table of doses, no age or weight adjustment, and no built-in target. If you want it to compare against a particular authority's figure, you have to find that figure and enter it, which is a deliberate design choice rather than an omission.
How to Use It
- Read the supplement facts panel, not the front label. Find the milligrams of EPA and the milligrams of DHA per capsule or per serving.
- Check whether the panel is per capsule or per serving. A serving is often two or three capsules, and reading a per-serving figure as per-capsule inflates the result by that multiple.
- Enter the number of capsules you take in a day, and optionally the total oil per capsule so the page can show the concentration.
- Enter a reference figure from a source you can name. Note the jurisdiction it came from and whether it refers to total omega-3, to EPA and DHA combined, or to a supplemental intake on top of diet.
- Take the result to a clinician or pharmacist if you are on any medication, have a bleeding disorder, are pregnant, or are considering a large intake.
The Formula and How It Is Calculated
The arithmetic is deliberately plain. Daily EPA equals EPA per capsule multiplied by capsules per day. Daily DHA is the same with the DHA figure. The headline is their sum. The share of the reference is the combined total divided by the reference figure, expressed as a percentage, and the concentration is the combined per-capsule EPA and DHA divided by the total oil per capsule.
With the default values — 180 mg EPA and 120 mg DHA per capsule, two capsules a day, 1,000 mg total oil, and a 500 mg reference — the page reports 360 mg EPA, 240 mg DHA, 600 mg combined, 120% of the reference figure entered, and a concentration of 30%. Those figures are typical of a standard, unconcentrated fish oil, and the 30% is the number most people have never checked.
Why "1000 mg Fish Oil" Is Not 1000 mg of Omega-3
The single most common misreading of a fish-oil label is treating the headline weight as the omega-3 content. A 1,000 mg capsule is a capsule containing one gram of fish oil. In a standard, unconcentrated product, roughly a third of that gram is EPA and DHA; the rest is other fatty acids and the oil matrix. Concentrated products push the proportion much higher — some reach 70% or more — but a shopper comparing two bottles by the number on the front is comparing capsule sizes rather than omega-3 content.
This is why the calculator asks for EPA and DHA separately rather than a single omega-3 figure. It is also why the "EPA+DHA as % of the oil" box exists: it converts the label into a like-for-like measure so two products can be compared honestly. A larger capsule at a lower concentration and a smaller capsule at a higher one can deliver the same milligrams, at very different swallowing volumes and prices.
Why Authorities Publish Different Figures
There is no single global omega-3 recommendation, and treating one country's number as universal is a mistake. The figures differ because the questions differ. Some authorities publish a dietary target expressed in portions of fish rather than milligrams; some publish an adequate intake for alpha-linolenic acid, the plant-derived short-chain omega-3, which the body converts to EPA and DHA only inefficiently; some publish a tolerable upper intake for supplemental EPA and DHA, which is a safety ceiling rather than a target; and some publish figures specific to pregnancy or to people with established cardiovascular disease.
Two examples worth reading in full rather than paraphrasing. The United States National Institutes of Health Office of Dietary Supplements publishes a fact sheet titled Omega-3 Fatty Acids: Fact Sheet for Health Professionals, which sets out adequate intakes, the evidence base, and the interaction considerations. The European Food Safety Authority published a 2012 opinion titled Scientific Opinion on the Tolerable Upper Intake Level of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA). Those documents are the primary sources; this page deliberately does not summarise their numbers into a single figure, because the conditions attached to each one are what make it meaningful.
Food First, and the Portion Route
Most dietary guidance frames long-chain omega-3 in terms of fish rather than capsules. The NHS advises that we should eat at least one portion, around 140 g cooked, of oily fish a week, while advising that girls, women planning a pregnancy and women who are pregnant or breastfeeding have no more than two portions of oily fish a week because of pollutants that accumulate in the fish. The World Health Organization's healthy diet fact sheet frames the same territory as a fat-quality question, treating the unsaturated fat found in fish, nuts and plant oils as preferable to saturated fat.
The tension in that advice — eat oily fish, but not too much of it — is the reason a mercury check belongs alongside an omega-3 check. Our fish mercury calculator works the other side of the same plate, converting servings of a named species into an implied methylmercury intake against the published reference dose. Reading the two together gives a far more honest picture than either alone.
Bleeding Risk, Medication and Surgery
Long-chain omega-3 affects platelet function, and that is the reason fish oil appears on medication-interaction lists alongside anticoagulants such as warfarin and antiplatelet drugs such as aspirin and clopidogrel. The research picture on whether that translates into clinically meaningful bleeding is more nuanced than the interaction warning suggests, and it continues to develop. What does not change is who should be making the decision: if you take a blood thinner, have a bleeding disorder, are scheduled for surgery or a procedure, or are pregnant, the size of an omega-3 intake is a conversation with a prescriber, not an output of a web page.
There is a regulatory point behind this too. In many countries supplements are not licensed or tested the way medicines are, so the EPA and DHA figures on a label carry a manufacturer's assurance rather than a regulator's. Independent testing has repeatedly found products whose measured content differs from the panel. The calculator can only be as accurate as the label, and the label is not a guarantee.
Arb Digital builds content and tools where sourcing, jurisdiction and honest limits matter as much as rankings. If your category is one where a careless sentence is a liability, we will show you how we would frame it.
Browse Free Tools Talk to Arb DigitalCommon Mistakes to Avoid
- Reading the capsule weight as the omega-3 content. A 1,000 mg capsule commonly supplies around 300 mg of EPA and DHA combined.
- Confusing a serving with a capsule. If the panel says "per 2 softgels", halve it before entering a per-capsule figure.
- Treating ALA and EPA/DHA as interchangeable. The plant-derived short-chain omega-3 in flax or walnuts converts to EPA and DHA only inefficiently, so gram-for-gram comparisons mislead.
- Borrowing a reference figure from another country without checking whether it describes a dietary target, a supplemental intake, or an upper safety limit.
- Adding a supplement on top of medication without telling a prescriber, particularly anticoagulants and antiplatelet drugs, or before a planned procedure.
Related Free Tools From Arb Digital
Pair this with the fish mercury calculator to see the other side of an oily-fish habit, and the macro calculator if you are tracking fat intake more broadly. The fibre intake calculator and the water intake calculator cover other published dietary reference figures, the percentage calculator handles the share arithmetic on its own, and the unit converter deals with milligram and gram conversions. The full free online tools hub lists everything else.
Frequently Asked Questions
It depends entirely on the product. In a standard unconcentrated fish oil, roughly 300 mg of that gram is EPA and DHA combined, often around 180 mg EPA and 120 mg DHA. Concentrated products can be far higher. The only reliable source is the supplement facts panel on the bottle you actually hold.
This page does not answer that, deliberately. Published reference figures differ between authorities and by circumstance, and intake is a clinical matter for anyone on anticoagulant or antiplatelet medication, anyone with a bleeding disorder, and anyone pregnant or breastfeeding. Ask a clinician or pharmacist and enter their figure into the reference field.
They are two different long-chain omega-3 fatty acids found together in marine oils. Products vary widely in the ratio between them, and some guidance is written for one specifically rather than for the combined total, which is why this calculator reports them separately as well as together.
Not directly. Flax, chia and walnuts supply alpha-linolenic acid, a shorter-chain omega-3 that the body converts to EPA and DHA only inefficiently. A gram of ALA is not equivalent to a gram of EPA and DHA, and reference figures are usually written for one or the other rather than both.
That is a question for the prescriber who manages your medication. Long-chain omega-3 affects platelet function and appears on interaction lists with anticoagulants and antiplatelet drugs. Do not start, stop or change a supplement alongside those medicines on the basis of a calculator.
Because there is no single global figure. Different authorities publish dietary targets, adequate intakes for plant-derived omega-3, and upper safety limits for supplements, each with conditions attached. Requiring you to enter a figure you can name keeps the source visible rather than hiding it inside the tool.
In many countries supplements are not licensed or tested in the way medicines are, so label figures carry a manufacturer's assurance rather than a regulator's. Independent testing has found products whose measured content differs from the panel. This calculator can only be as accurate as the numbers you enter.
This tool performs arithmetic on figures you supply and does not recommend any intake of omega-3, EPA or DHA. It is not medical advice. Published reference figures differ between national authorities and by circumstance. Speak to a clinician or pharmacist before starting or changing a supplement, particularly if you take anticoagulant or antiplatelet medication, have a bleeding disorder, are due to have surgery, or are pregnant or breastfeeding.
