How long will a bag of dog food last?

Updated 8 November 2026

Divide the weight of the bag by the amount your dog eats each day. The answer is the number of days the bag will last.

The sum

Bag weight in grams ÷ grams per day = days. A kilogram is 1,000 grams, so a 12 kg bag holds 12,000 grams.

As an example, a dog eating 300 g a day will get through that bag in 40 days (12,000 ÷ 300). The dog food calculator does this for you and gives the date the bag runs out.

Why a bag can run out early

• Scooping by eye instead of weighing, which can drift over time.
• More than one dog eating from the same bag. Add their daily amounts together first.
• A change of portion after a vet visit or a change in activity.

When to order the next bag

Count back from the run-out date by the delivery time your retailer quotes, then add a few days for delays. Buying in good time also gives you room to mix old and new food if you are changing brand.