Net Carb is a short form for Net Carbohydrates. When calculating this value, you subtract the fibre from the total carbohydrate count to get your value. We do this because fibre passes through your body and isn’t ingested. Therefore we don’t need to count it in our carb count. We also subtract sugar alcohols from this value (Erythritol).
100g of Strawberries have 7g of carbs. However, 100g of strawberries also have 2g of fibre. So 100g of strawberries has 5g of NET carbs. 7g(total carbs) – 2g(fibre) = 5g NET.