How much each figure is worth believing

Every profit figure this extension prints rests on one number OpenCart does not have: what the goods cost you. So every line it records carries a cost basis saying where that number came from, and every screen, export and API row carries it forward. A period is only as good as the bases underneath it.

Basis	What it means	How a line gets it	In the totals?
actual	The cost you had recorded against that product when the order became real.	You typed it on the product form, or imported it from the cost CSV, before the order was placed.	Yes. This is the only basis that is a measurement rather than an assertion.
estimated	Derived from your default margin, because the product had no cost of its own.	You set a default margin under Settings > Costs and left this product uncosted.	Yes, and it moves your reported profit. A margin you guessed is a profit figure you guessed.
backfilled	Recomputed after the fact, at a cost you recorded later than the order.	You ran Recalculate from a date, or the opt-in back-fill, over a period that had already been recorded, or Recalculate this order on one order.	Yes. It is never downgraded to anything else afterwards, so a line that was backfilled stays labelled as one.
unknown	Nobody has said what this product costs, and nothing was invented.	The product has no cost, and there is no default margin set.	No — and the line is out of the revenue as well as out of the cost, which is what stops an uncosted sale reading as pure profit. What it sold for is reported separately as excluded revenue.

The order above is the order of authority, least qualified last. Where a product's lines in one period do not all share a basis, the product is labelled with the least authoritative of them and the mix is shown beside it — so a product that is mostly measured and partly guessed reads as partly guessed, which is the way round that cannot mislead you.

The one that is not a number

unknown is the basis that changes what is counted rather than what is believed. An uncosted line is excluded from the cost of goods and from the revenue, and its sales value is reported as excluded revenue beside the coverage figure. Counting the revenue and calling the cost zero would make an uncosted product look like your best one, which is the single most expensive mistake a margin report can make.

Coverage below 80% of the period's lines is called out on the dashboard. That is the ordinary state for the first week after install and is designed rather than degraded: the figures are frozen forward from the day you switch the extension on, and Recalculate from a date is what reaches back over what came before.

Nothing is ever repriced

Changing a product's cost today does not change a single figure already recorded. That is deliberate: a closed month that moves because somebody updated a supplier price is a month you cannot reconcile against anything. Recalculate is the one door back, it is explicit, and everything it touches is relabelled backfilled so a reader can tell.