Know the calculation

Different numbers answer different questions.

1. Reconcile units

Opening units + new units made must equal full-price sales + discounted sales + donations + waste + carried units. Each physical unit belongs in exactly one ending category. The calculator reports the unexplained difference.

2. Enter cost snapshots

Opening stock total cost is the value carried from earlier stock. New production cost is new units × your entered cost per unit. Include the costs relevant to your decision; omitted labor, packaging, travel or overhead will not be inferred.

Itemize event costs

Keep labeled event costs separate from costs already included in production. An older expense total migrates as one line; replace it when entering its component detail to avoid double counting. Read the itemized cost and private-reference guide.

3. Allocate used and carried stock

The tool combines opening and new stock costs, allocates a proportional share to carried units and rounds that share to cents. The remainder belongs to sold, donated and wasted stock. Used cost plus carried cost always equals the entered stock-cost total when quantities reconcile.

4. Read both measures

Event contribution = sales less entered refunds − stock used cost − event expenses. Cash after new production and expenses = sales less entered refunds − new production cost − expenses. That cash measure excludes money previously spent on opening stock. Neither measure is accounting profit, actual bank cash or a tax calculation.

Refunds and returns

A money refund reduces receipts but does not change physical stock. Record each physical unit's final disposition yourself. The current tool does not track return transactions or tax separately. Enter reviewed sales amounts consistently; it does not reconcile your payment processor.

Carryover

After all units reconcile, enter a later event's name and date and download its file. The original stays unchanged. The next file starts with leftover stock and its cost, zero new production and zero expenses. This is a snapshot, not a shared stock allocation: do not use the same stock twice.

Save and limits

Save explicitly or download a backup before closing. Up to 100 products and 100 event costs, whole unit counts, USD amounts with two decimals and at most $1,000,000 stock cost per product. Imported files must be under 1 MB.