Every number here comes from NRC & WSAVA methods and is published as open data (CC BY 4.0). See how we check our numbers →
At the site-standard 110 g per cup, a 30 lb bag holds about 124 cups; a 5 lb bag about 21, a 15 lb bag about 62, and a 50 lb bag about 206. The one number that moves the answer is how much your scoop actually weighs — at 100 g/cup a 30 lb bag is 136 cups, at 120 g/cup it is 113.
Part of our feeding guides index — every calculator and chart on the site in one place.
Most people ask this to work out cost per meal or whether a bag is worth buying. The conversion is simple, but it depends on one thing you have to check on your own food.
Calculated as bag weight in lb × 453.592 ÷ grams per cup. The middle column (110 g) matches the rest of this site; the outer columns show how much the answer moves if your food is lighter or denser.
| Bag size | @100 g/cup | @110 g/cup | @120 g/cup |
|---|---|---|---|
| 5 lb | 23 | 21 | 19 |
| 15 lb | 68 | 62 | 57 |
| 24 lb | 109 | 99 | 91 |
| 30 lb | 136 | 124 | 113 |
| 40 lb | 181 | 165 | 151 |
| 50 lb | 227 | 206 | 189 |
A cup is a measure of volume, a bag is sold by weight — so you cannot convert one to the other without knowing how heavy your kibble is per cup. Two bags both sold as "30 lb" hold very different numbers of cups if one kibble is light and airy and the other is dense and small.
The good news: you can find out in about a minute. Weigh one level cup of your own food on a kitchen scale. If you get 90 g, use the light column; 130 g, lean the other way. Reading the calorie panel explains where the numbers come from.
Cups per bag is what turns "price per bag" into "price per meal". Divide the number of cups by how many cups your dog eats a day and you get the days a bag lasts — the bag duration calculator does that step for you by your dog’s weight.
For the other direction — working out what a single cup is worth in calories — see how many calories are in a cup of dog food.
Does the bag weight include the bag? Net weight is the food, not the packaging, so use the net figure on the label.
Why does my bag say "approx. 4 cups per lb"? That is roughly 110 g per cup. It is an average for that specific food — your scoop may not be exactly a measuring cup.
Is a 50 lb bag cheaper per cup? Usually per cup yes, but the food also has to stay fresh. See how long dry dog food lasts before buying the biggest bag.
Buying dry food? Browse dry dog food on Amazon — check the kcal per cup on the label against your dog’s daily target before you commit to a bag size.
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How long a bag lasts → · Calories per cup → · Cups in a pound → · Feeding calculator →