How to Calculate Carbohydrates in a Pet Food


Do you ever wonder why carbohydrates aren’t listed as a percentage on a pet food label?
In canine nutrition what matters most is protein, fat, and other nutrients. A dogs need for carbohydrates is questionable, and you may find yourself wondering if dogs need carbohydrates at all?
Yes, I’ve heard the argument dogs are omnivores like us, but they’re definitely not like us. They have many more similarities in nature and cold hard biological facts to a cat as an obligate carnivore.
Not even pet food manufacturers, scientists, or professors have been able to give me a logical answer as to why so many cat foods are high-carbohydrates, which questions whether dog foods should be either.
Let’s take a look how to calculate carbohydrates in pet food, and you’ll find a simple carbohydrate calculator below to do the dirty work for you (who likes maths anyway?)
How to calculate carbohydrates in a pet food
Carbohydrates don’t need to be listed on the label of pet foods in Australia, but we can use a simple calculation to offer us a rough idea.
It’s not perfect, and I’ll explain why, but the following method is how to calculate carbohydrates in a pet food:
100 – Protein % – Fat % – Moisture % – Ash %
If moisture and ash are not listed on your pet food, you may use average values of 10% moisture and 8% ash for a dry pet food.
Wet food, air-dried, freeze-dried, BARF et al will have differing amounts of moisture, so take that into account.
Carbohydrate calculator
Here’s a carbohydrate calculator for dog food and cat food for your convenience.
The above calculator will give you a rough idea, but there’s a little more to it than that.
Other factors to consider are undisclosed moisture and ash percentages and variance from min & max percentages.
Moisture & Ash
Moisture and ash are usually listed, but as these percentages aren’t required to be listed we can use an average 10% moisture and 8% ash for dry food only. Wet foods contain significantly more moisture.
Min & Max
We often find percentages are listed with a guaranteed minimum or maximum. This makes our simple calculation somewhat vague. If a pet food contains Protein (min) 20% then it’s possible the protein, on average, is higher.
How to Calculate Carbohydrates: An example
Let’s say a dry dog food contains 20% protein, 10% fat, 10% moisture, and 8% ash:
100 – 20 – 10 – 10 – 8 = 52
This product would contain approximately 52% carbohydrates.
So that’s it, that’s how to calculate carbohydrates in a pet food.