Why the old drop-multiplier model was removed
The previous calculator multiplied a user-entered base chance by Pack Size, a Scarab percentage, and an Atlas percentage. Path of Exile has no published universal rule saying those three labels multiply every currency, card, chest, mechanic reward, or monster outcome. The same page then multiplied that synthetic chance by a fixed average value and forced negative hourly profit to zero. Precise output from an unsupported transform is less useful than straightforward accounting from visible inputs.
Official updates establish a moving ruleset
Grinding Gear Games' 3.28.0 notes describe extensive endgame and Atlas changes, including changes to map-device inputs, map quality, reward modifiers, Atlas passives, maps, and scarabs. The 3.27.0c notes also changed several scarab limits or effects in a minor patch. These primary sources demonstrate why an old route table cannot be silently relabeled as current. They do not publish a reusable gross-return figure for your build, execution, league economy, and chosen batch.
GGG: Content Update 3.28.0
GGG: 3.27.0c patch notes
Official Path of Exile Trade
Choose an observed batch or a what-if batch
An observed batch uses actual maps, costs, returns, and elapsed time. A what-if batch uses clearly labeled assumptions to compare a proposed change. Both can use the same arithmetic, but they are different evidence. Do not describe a what-if gross return as a measured result. Put the distinction in the scenario label and store the raw log beside the shared URL.
Use one valuation timestamp and boundary
Decide what “gross return” includes. You may count only currency already converted into the shared unit, or include priced items under a documented method. Apply the same method and timestamp to every cost. Listed price, executable price, and realized sale price can differ; unsold, illiquid, or retained items should not be treated as guaranteed cash. If an official Trade snapshot informs the value, record the league, query, timestamp, stack size, and whether the listing was actually available.
Keep every amount inside the batch boundary
Gross return and the three cost fields are totals, not per-map values. Map acquisition or preparation cost can include the map item and any currency consumed to prepare it under your stated method. Fragments and scarabs have a separate field so a reviewer can see the largest add-on category. Other direct costs capture remaining consumed inputs. Do not put a per-map scarab price beside a ten-map gross return.
Use a complete session clock
Start before acquisition or preparation when those tasks belong to the comparison. Include mapping, mechanics, looting, loading, deaths, failed maps, stash work, valuation, and selling time as defined. Stop at a comparable state. A “net per hour” value that excludes an hour of trading from one strategy but includes it for another is not a fair comparison even when the subtraction is correct.
How the outputs are calculated
Total direct cost is the sum of the three cost fields. Net batch return is gross return minus total direct cost. Per-map figures divide by the whole-number map count. Per-hour figures divide by the complete session duration in hours. Break-even gross equals total direct cost. Net margin divides net return by gross return when gross is positive. No probability, Atlas node, scarab, map name, league label, or price source enters these formulas.
Compare scenarios without hiding losses
Save a baseline URL, duplicate it, and change one variable. A negative result stays negative so the cost of the change remains visible. If several elements change at once, the new output describes the new batch but cannot identify which change caused the difference. Repeat observed batches before generalizing from a lucky or unlucky window, and retain the raw observations rather than publishing invented sample rows.
Continue with the evidence workflow
The evidence-first PoE map accounting guide provides a source checklist, valuation rules, comparison method, and blank batch-log schema.