Real Cost per ml Calculator with Product Waste
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When you buy 1 ml and use 0.85 ml, the ml you used cost more than the sticker price. That is the real cost per ml: what you paid divided by what was actually applied. Ignoring it leaves your selling price lower than it needs to be.
The calculator shows the effect of waste on cost and margin. Your data stays in your browser, and the starting values are a hypothetical example.
What does each field mean?
| Field | What to enter |
|---|---|
| Package cost | What you paid, including shipping and taxes. |
| ml in the package | The total volume of the package. |
| Waste | Percentage that does not reach the patient: discarded leftovers, expired product, residue in the syringe and the cannula. |
| Price charged per ml | The amount you charge the patient per ml. |
How is it calculated?
- Cost per ml purchased = cost ÷ ml.
- Cost per ml used = cost ÷ (ml × (1 minus waste)).
- Increase = used minus purchased.
- Profit per ml = price charged minus cost per ml used (before other costs).
Worked hypothetical example
Hypothetical example: a R$ 700.00 package with 1 ml, 15% waste and a price of R$ 1,500.00 per ml.
| Step | Calculation | Result |
|---|---|---|
| Cost per ml purchased | 700 ÷ 1 | R$ 700.00 |
| Cost per ml used | 700 ÷ 0.85 | R$ 823.53 |
| Increase from waste | 823.53 minus 700 | R$ 123.53 |
| Profit per ml | 1,500 minus 823.53 | R$ 676.47 |
| Margin on price | 676.47 ÷ 1,500 | 45.1% |
How do I use the result?
Use the cost per ml used as the basis for your price in the price per ml and margin calculator. To understand the effect of larger or smaller packages on leftovers, see the syringe yield. To cut losses from expiry, calculate the cost of idle inventory, and to compare suppliers, use the comparison by ml.
Frequently asked questions
What is the difference between cost per ml purchased and cost per ml used?
Cost purchased divides the price by the ml in the package. Cost used divides by what was actually applied to the patient, after deducting waste.
How do I estimate the waste percentage?
Add up what you discard over a period (leftovers, expired product, residue) and divide it by what you bought in the same period.
Can leftover product in the syringe be used on another patient?
No. Opened product is single use according to the package insert, and the leftover is discarded. The calculator treats this only as a financial cost.