A 12 kg package costing USD 48 contains 12,000 grams. At an already-selected 200 grams per day for one pet, it supplies 60 days and costs USD 0.80 per day. Those figures describe use, not a serving recommendation or how long opened food stays suitable to feed.

Over 30 days, the same example uses USD 24 worth of food. If you have no stock, you still buy a whole USD 48 package. The remaining 6 kg stays in the inventory calculation. A lower consumption cost and a smaller checkout bill are different decisions.

Enter the package and the ration you already use

Start with the exact food and formulation. Enter the package’s net food mass, excluding its bag, can or container. For a multipack, use the combined food mass and the total price of the same purchase. Apply delivery, tax and discounts consistently; a coupon that does not apply is not part of the entered price.

The daily field is grams per pet of this exact food, using the ration already selected from its label or appropriate individual guidance. Multiply only pets using that same amount and food. If one pet eats 150 g and another eats 200 g, make separate records rather than entering two pets at 200 g.

Unknown fields stay blank. Zero price means an explicitly entered zero price; it does not stand for a missing price. Zero stock means no usable food at home. Unknown stock prevents a refill-purchase estimate.

Read the four different results

Result Calculation What it answers
Unit price Total paid price divided by net kilograms What the same mass costs
Package duration Net grams divided by entered household grams per day How long that quantity lasts at constant use
Consumption value Price per gram multiplied by grams used The value of food used each day or over the chosen period
Refill purchase Uncovered demand divided by package mass, rounded up to whole packages How many packages to buy after known stock

The tool displays fractional duration and the number of whole days separately. A result of 7.5 days contains seven complete days at the entered use, plus half another day. It does not supply an order date or delivery buffer.

Consumption value assumes the entered package price continues to apply. Checkout cash multiplies the whole-package count by that price. Price changes, spoilage, unrecorded food use, subscriptions and delivery timing can change what actually happens.

Plan a refill with known stock

Open the refill panel and enter the whole days you want to cover, plus known usable grams already at home. The tool subtracts that stock from total planned use, with a minimum uncovered demand of zero. It then rounds the required package count up without rounding the food amounts first.

For the fictional 12 kg package and 200 g/day example:

Thirty-day starting stock New packages Checkout cash Food remaining after 30 days
Unknown Unknown Unknown Unknown
0 g 1 USD 48 6,000 g
6,000 g 0 USD 0 0 g
6,500 g 0 USD 0 500 g

These rows assume all recorded stock remains usable. They do not authorize retaining opened food for the calculated period. Follow the actual storage instructions and check the label, condition and relevant recall information separately.

Compare package sizes of the same food

Package B is optional. Its unit price can be calculated independently, but it does not inherit A’s ration and stock until you explicitly confirm the same formulation and applicable ration. That confirmation is a reader record, not an independent identity check.

In the fictional example, 6 kg at USD 25 costs more per kilogram than 12 kg at USD 48. Yet covering 30 days from zero stock requires one package either way: USD 25 for the smaller package or USD 48 for the larger. The smaller checkout bill does not mean a lower daily consumption cost.

A price-per-kilogram comparison cannot select a diet. FDA explains that nutritional adequacy and life stage matter, and that moisture differences affect comparisons between food formats. Wet and dry foods, different recipes, treats and therapeutic diets do not become interchangeable because their unit prices can be calculated.

Changing an identity clears that package’s mass and price for re-entry. Changing A also clears the shared ration, pet count and stock because the food may have changed. Other edits clear previous same-food confirmation and source notes. Currency selection changes the label on your amounts; it applies no exchange rate.

Package duration is not a storage deadline

FDA advises retaining the original packaging and its product, lot and best-by information. For dry food kept in another container, FDA recommends keeping the whole bag inside it where practical. Those records matter if there is a product problem or recall.

The calculator supplies no universal opened-bag lifetime or wet-food handling interval. A package lasting 60 days in the arithmetic does not establish that its contents remain appropriate to use for 60 days. A larger bag’s lower unit price must be considered alongside the actual label and storage routine.

What this tool leaves unresolved

  • Which food or formulation is appropriate for an individual pet.
  • Calories, grams to feed, treats, mixed diets or changes in nutritional needs.
  • The relationship between cups, cans or scoops and grams without food-specific information.
  • Actual future prices, availability, delivery dates or subscription terms.
  • Whether recorded stock remains usable, or any opened-food storage deadline.
  • Whether the reader-confirmed package B is actually the same formulation.

After the arithmetic, the dry dog food buying guide and dry cat food buying guide cover product-selection questions. If part of an already-selected ration goes into a dispenser, the KONG Wobbler review explains the difference between a filling capacity and a serving recommendation. Return to the pet-care guide library for other setup questions.

Method, sources and record keeping

This is an original deterministic calculation using reader-supplied net mass, paid price, selected ration, pet count, planning period and usable stock. Whole-package rounding uses exact integer arithmetic after mass normalization. Displayed costs round to at most four decimal places and quantities to three; nonzero costs below USD 0.0001, or the corresponding selected currency, are labeled as positive rather than zero. Inputs are not live product specifications, retailer prices or measured feeding trials.

Primary sources were read October 20, 2026:

CSV and native print retain the actual inputs, currency, formulation notes, source references, stock, comparison confirmation, separate consumption/purchase results and limitations. Entries remain in this tab without automatic saving, an account, server calculation or new tracking. Export before closing.