Ingredient mass inventory

Concentration is a ratio; inventory is an amount

A label such as 10 mg per 1 mL describes how much of one ingredient is associated with a volume of the labeled material. It does not tell you how much material is currently in a container. For inventory, you need the concentration, the known filled volume and the number of matching containers.

This worksheet first normalizes each ratio to mg/mL. It then applies that ratio to each container's entered volume, before adding ingredient masses. You can use differently written ratios without treating every container as if it had the same concentration.

Example: two label styles, one ingredient total

Suppose an illustrative sodium chloride inventory has two containers, each with 100 mL at 10 mg per 1 mL. Each holds 1,000 mg on the label basis, for a first-row subtotal of 2,000 mg.

A third container holds 0.25 L at 0.2 g per 100 mL. That ratio is 2 mg/mL and its filled volume is 250 mL, giving 500 mg. The complete inventory is therefore 2,500 mg = 2.5 g. The sum of the entered volumes is 450 mL across three containers. These are bookkeeping totals; the app does not instruct you to mix their contents.

Choose what belongs in one row

• Same concentration and fill: a row with a count of three applies the entered filled volume to each of those three containers. Do not enter the combined volume and then multiply by the count again.
• Partial containers: use a separate row with the actual known remaining volume. Container capacity or original package size is not a measurement of what remains.
• Same named ingredient: identical-looking numbers may refer to different chemicals, salts, or reporting forms. Confirm the basis before totaling; this app cannot identify chemical equivalence from a name.
• Known mass-per-volume ratio: a bare percentage, ppm value or total-mass-only label is insufficient here. Resolve its stated basis first, instead of assuming mg/mL.

Reading the inventory result

Each result line shows concentration, ingredient per container, count and the row subtotal. The final mg and g amounts refer to the named ingredient, not the total mass of all liquid and packaging. The volume sum describes the original containers; it is not a prediction of a combined solution's final volume or concentration.

Zero filled volume is allowed for an empty container, while label mass and label volume must be positive. Counts must be whole numbers from 1 to 1,000,000. Up to eight rows are supported. The total is based on entered concentration and fill, not a guarantee of recoverable material, label assay accuracy or uniformity in an unsettled sample.

Check the labels before adding them

The concentration label converter helps separate a label ratio from package volume. The two-label comparison checks the relative strength of two confirmed ratios. For a single amount and known concentration, use the mg to mL converter.

Inputs start blank, and changing a unit clears its number so an earlier amount cannot silently acquire new units. Copyable results retain the ingredient name and unit basis. All calculations run locally, without saving your inventory.

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