What are net carbs? How to calculate net carbs in dog food
Apr 18, 2026
What are net carbs? How to calculate net carbs in dog food
If you're trying to feed your dog a low-carb or ketogenic diet, total carbohydrates on a label can be misleading. The number that actually matters is net carbs — and most dog food brands don't make it easy to find.
What are net carbs?
Net carbs are the carbohydrates that your dog's body can actually digest and convert to glucose. The formula is simple:
Total carbohydrates − dietary fibre = net carbs
Not all carbohydrates behave the same way in the body. Dietary fibre — whether soluble or insoluble — cannot be fully digested and converted to glucose. Because fibre doesn't raise blood sugar, it doesn't count toward net carbs.
Everything else does. Starches, sugars, and other digestible carbohydrates all count as net carbs because they directly raise blood glucose and trigger an insulin response.
Why net carbs matter specifically for dogs
Dogs have no nutritional requirement for carbohydrates. Unlike humans, they produce very little amylase — the enzyme that breaks down starchy carbs — and their metabolism is optimised for fat and protein as fuel sources.
When a dog eats digestible carbohydrates, blood glucose rises and the pancreas releases insulin to manage it. A diet consistently high in net carbs means this cycle repeats multiple times daily, contributing over time to insulin resistance, weight gain and elevated diabetes risk.
This is why net carbs — not total carbs, not sugar content specifically — are the most meaningful number when evaluating a dog food.
How to calculate net carbs in dog food
Most dog food labels list total carbohydrates and dietary fibre separately. Simply subtract fibre from total carbs:
Example: a dog food with 28g total carbohydrates and 4g dietary fibre has 24g net carbs per serving.
The challenge is that many dog food brands don't clearly list carbohydrate content at all. Unlike human food, there's no regulatory requirement to disclose carbs on a pet food label — which is why so many brands obscure this information.
If carb content isn't listed, you can estimate it using the guaranteed analysis on the label. Add up the percentages for crude protein, crude fat, crude fibre, moisture and ash — then subtract from 100. The remainder is the approximate carbohydrate percentage. Note this gives you total carbs, not net carbs, since the fibre figure used in guaranteed analysis is crude fibre rather than total dietary fibre.
What to look for
For a dog food to be genuinely low carb, net carbs should be under 5% of total calories — ideally closer to 1% or less. Most standard dry kibble sits at 30–60% carbohydrates by caloric content, making net carbs the critical differentiator between foods that are marketed as healthy and foods that actually are.
When evaluating any dog food, look for brands that list carbohydrate content clearly and transparently rather than omitting it from the label entirely.
This post is for informational purposes only and does not constitute medical advice. Always consult a qualified veterinarian regarding your dog's specific dietary needs.
