Pet Food Calculator
How much to feed a pet each day scales with its body weight, and knowing that daily amount tells you exactly how long a given bag will actually last before running out.
Inputs
Result
450 g / day
A 12 kg bag lasts 27 days
How the pet food calculator works
Daily feed (g) = pet weight (kg) × daily feed percentage ÷ 100 × 1,000.
Days a bag lasts = bag size (kg) ÷ daily feed (kg).
Worked example: 18 kg pet, 2.5% daily feed, 12 kg bag
- Daily feed = 18 × 2.5 ÷ 100 = 0.45 kg = 450 g per day.
- Bag lasts = 12 ÷ 0.45 ≈ 26.67, rounds to about 27 days.
Common mistakes to avoid
Using a generic feeding percentage instead of the specific food's guidance
Recommended daily feed percentage varies by food brand, calorie density, and the pet's age, activity level and health status — always check the specific product's feeding guide rather than assuming one universal percentage fits every situation.
Not adjusting for weight changes over time
As a growing puppy or kitten gains weight, or an adult pet's weight changes, the daily feed amount calculated here should be recalculated periodically rather than left fixed indefinitely.
Frequently asked questions
Why is daily feed given as a percentage of body weight rather than a fixed amount?
It scales feeding appropriately across different sized pets — a fixed gram amount that's right for a small dog would badly underfeed a large one, so percentage-of-bodyweight is the more universal starting guide.
How accurate is the typical 2-3% range often quoted for dogs?
It's a reasonable general starting point for adult maintenance, but puppies, very active dogs, and pets needing weight management often fall outside that range — check the specific food's packaging guidance for the most accurate figure.
Does this work the same way for cats?
The same percentage-based logic applies, though typical percentages and feeding guidance differ from dogs — always use the specific product's recommended feeding amount for the pet's actual weight.
How do I use the 'days a bag lasts' figure practically?
It's useful for timing reorders in advance, so a new bag arrives before the current one runs out, especially for pets on a specific prescription or specialty diet with longer delivery times.
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