Dog Food Bag Calculator
How long a bag of dog food lasts, how many cups are in it, and what feeding costs a day, a month and a year.
Result
Enter weight of one cup of this food and cups per dog per day to see the result.
https://calcgallery.com/pets/dog-food-bag-calculator/
Results are arithmetic on the figures you enter and are estimates. Products, materials and animals vary, so follow the maker's instructions and label, make a test piece where it matters, and ask a vet about feeding. Nothing here is safety or veterinary advice. Read the full disclaimer
How to use the Dog Food Bag Calculator
- Enter the weight of the bag from its label.
- Choose whether you measure food in cups or by weight.
- For cups, enter the weight of one cup of this food, or the two figures under "Calorie Content" on the bag, and the cups each dog gets a day.
- For weight, enter the grams or ounces each dog gets a day.
- Enter how many dogs eat from the bag, and the price if you want the cost.
How it is calculated
food a day = amount per dog × dogs (amount per dog = cups × weight of a cup, when you use cups)days = bag weight ÷ food a daycups in bag = bag weight ÷ weight of a cupbags a year = ⌈365 ÷ days⌉cost a day = bag price ÷ bag weight × food a dayWhen the weight of a cup is worked out from the calorie statement, it is kcal per cup ÷ kcal per kilogram. That inverts AAFCO’s own example, where a food of 3,688 kcal/kg at 120 grams a cup has 442.6 kcal a cup. Since a cup weighs less than a kilogram, the kcal per kilogram figure is always the larger of the two; if the figures entered give a cup lighter than 5 grams or heavier than a kilogram, the page shows no result and asks you to check that they are not swapped.
Cups are not all the same
A cup of large, airy kibble weighs less than a cup of small, dense kibble, so the same number of cups from two bags can be quite different amounts of food. The weight of a cup on the label, or one you weigh yourself, keeps the answer tied to your food. Scoops sold with food are often not a standard measuring cup; weigh a scoop the same way if that is what you use.
With your numbers
- Food a day = 2 cups × 120 g × 1 = 8.5 oz
- Days = 30 lb ÷ food a day = 56.7
Quick reference
This uses the amount you feed; it does not say how much a dog should eat. Ask your vet about that.
| Example | Days the bag lasts |
|---|---|
| 30 lb bag, 2 cups a day, 120 g a cup | 56.7 |
| 30 lb bag, 3 cups a day, 100 g a cup | 45.4 |
| 40 lb bag, 2 dogs at 2 cups each | 39.4 |
| 4 lb bag, half a cup a day | 36.3 |
| 30 lb bag, 3,688 kcal/kg and 442.6 kcal/cup | 56.7 |
| 12 kg bag, 300 g a day | 40 |
| 15 kg bag, 2 dogs at 250 g | 30 |
Common questions about the Dog Food Bag Calculator
- How many cups are in a 30 lb bag of dog food?
- It depends on the kibble. At 120 grams a cup, a 30 lb bag (13.6 kg) holds about 113 cups; a lighter kibble at 100 grams a cup gives about 136. Cup counts on forums vary because kibble sizes and densities vary, which is why the page asks for the weight of a cup of your food.
- The bag does not say how much a cup weighs. How do I find it?
- Pet food labels in the US carry a "Calorie Content" statement in kcal per kilogram and kcal per cup. AAFCO explains that kcal per cup is kcal per kilogram divided by 1,000, times the grams in a cup, so grams per cup is kcal per cup divided by kcal per kilogram, times 1,000. Choose "Work it out from the calorie statement" and enter both figures, or weigh a level cup on a kitchen scale.
- How long does a bag of dog food last once it is open?
- This page answers how long it lasts at the amount you feed, not how long the food stays fresh. The bag's best-by date and the maker's storage advice cover freshness.
- How much should my dog eat?
- This page does not say. The feeding guide on the bag is a starting point, and your vet can tell you what suits your dog's weight, age and activity. Enter whatever amount you feed.
- How is the cost per month worked out?
- The cost per day is the bag price divided by the bag weight, times the food eaten a day. A month is taken as 365 ÷ 12 days, about 30.4, and a year as 365 days.