How to use the pet food run-out date calculator
- Enter the bag size and the grams you feed each day.
- Enter the date you opened the bag.
- Optional: add how many days notice you need to reorder.
Worked example
A 15 kg bag opened on 18 October 2026 and fed at 300 g a day, reordering 7 days ahead.
- Bag size
- 15 kg
- Grams fed per day (all pets)
- 300
- Date you opened the bag
- 2026-10-18
- Days before it runs out to reorder — optional
- 7
- Lasts
- 50 days
- Reorder by
- 30 Nov 2026
- Opened
- 18 Oct 2026
Opened bags go stale: follow the storage advice on the pack.
Example values are illustrative; this result is produced by the same calculator above.
How we calculate it
Sources: Pure arithmetic / unit conversion on user inputs (no external constant)
Understanding your result
Bag duration in days is the bag weight in grams divided by what you feed each day. A 15 kg bag at 300 g a day lasts 50 days. Adding that to the date you opened the bag gives the date it runs out: 7 December 2026 if you opened it on 18 October.
If you enter how many days' notice you need to reorder, the calculator also shows the reorder date, here 30 November 2026 with a 7-day lead time.
Include all pets and any toppers or treats from the same bag in the daily grams, so the date is realistic.
Common mistakes
- Using the date you bought the bag instead of the date you opened it.
- Forgetting that several pets share the bag.
- Not allowing delivery time.
- Counting treats and toppers from other packs.
- Ignoring the best-before date on opened bags.
Good to know
- Store food as the pack advises.
- The Pet Food Bag Duration Calculator gives the number of days.
- A calendar reminder a week before can prevent last-minute buying.
Using the reorder date
Enter the date you opened the bag, not the date you bought it, because the food starts to be used when it is opened. Use total grams a day for all the pets eating from the bag.
A 15 kg bag fed at 300 g a day lasts 50 days. Opened on 1 October it runs out on 20 November, and with a 7-day reorder lead the calculator suggests ordering by 13 November. Allow for delivery times and for holidays when couriers are slower.
If your pet's weight or the food changes, redo the sum. A food with a different energy density needs a different amount in grams, and the date moves with it.
Frequently asked questions
How is it different from the Bag Duration Calculator?
That tool gives the number of days. This one turns it into a calendar date and a reorder date.
What lead time should I use?
Think of how long delivery takes plus a few spare days.
Does it allow for treats and toppers?
Only if you add their grams to the daily amount.
What if I feed several pets?
Enter the total grams per day for all pets that share the bag.
How is this different from the Bag Duration Calculator?
That gives the number of days. This gives the calendar dates.
Does it allow for treats?
Only if you add their grams to the daily amount.
Sources
- Pure arithmetic / unit conversion on user inputs (no external constant)
Related calculators
- Pet Food Bag Duration CalculatorFind out how many days a bag of pet food will last at the amount you feed.
- Dog Food Cost CalculatorSee what it costs per day, month and year to feed your dog, from its calorie need and the price of the bag.
- Pet Food Cost per Meal CalculatorFind what each meal costs from the price of the bag and the grams you feed.
- Dog Food CalculatorTurn your dog's daily calorie need into grams and cups of the food you actually feed, using the energy value printed on the bag.
Estimates only. Every pet is different — confirm with your veterinarian.