You may need to maintain the recommended EPA+DHA intake for 4-5 months in order to meet your goal Omega-3 Index.
Use the estimate from the calculator to make a plan to increase your EPA+DHA intake. For example, the calculator may recommend you take 1235 mg EPA+DHA per day and to meet that goal you may take 1500 mg EPA+DHA per day because of the amount in your supplements. It is not necessary to match the calculated dose exactly.
While EPA+DHA intake is the primary driver of your Omega-3 Index, your genes and overall health can affect the Omega-3 Index response to dietary changes. Re-testing is the only way to determine whether you have achieved your target Omega-3 Index.
These calculations are based on results from a 5-month randomized, placebo-controlled fish oil supplementation study in 115 healthy individuals (Flock M et al. JAHA 2013).