Walnuts are a nutrient-dense snack, but if you are tracking sugar for diabetes management, low-carb eating, or general carbohydrate awareness, it helps to know exactly how much sugar your serving contains. This walnut sugar per 100g calculator converts your portion size — whether you measure in grams, ounces, cups, or whole kernels — into grams of sugar using the standard USDA value of 2.61 g of sugar per 100 g of raw English walnuts. You can also adjust the sugar-per-100g value if you are using a different product or a flavored walnut blend.
Use the quick-fill preset buttons for common portions, or type in your exact amount and choose a unit. Press Calculate to see the total sugar, the sugar per kernel, and a simple step-by-step breakdown of the math. This makes it easy to log walnuts in a food diary, compare nut options, and keep your daily sugar intake in perspective.
🥜 Walnut Sugar Calculator
Find out how many grams of sugar are in your walnut portion.
Portion amount
⚙️ Sugar reference
How to Use This Tool
Start by choosing the unit that matches how you actually measure your walnuts — grams, ounces, chopped cups, or whole kernel pieces. The calculator first converts whatever you enter into a gram weight, then applies the sugar reference value. The default reference of 2.61 g of sugar per 100 g is the standard USDA figure for raw, shelled English walnuts, so for plain walnuts you can simply type in your portion and press Calculate.
If you are using a different product — such as honey-roasted, candied, or a flavored walnut blend — check the nutrition label for its sugar content per 100 g and update the "Sugar reference" field before calculating. This keeps your results accurate even when the product is not plain raw walnuts.
The Math Behind It
The calculator works in two steps. First, it converts your portion to grams using these standard approximations:
- 1 oz = 28.3495 g
- 1 cup of chopped walnuts ≈ 120 g
- 1 walnut kernel ≈ 4 g
Second, it applies the sugar percentage:
For example, if a product label states 5 g of sugar per 100 g and your portion weighs 40 g, the calculation is 40 × (5 ÷ 100) = 2.0 g of sugar. The same formula works for any portion size, which is why nutrition labels express sugar per 100 g — it keeps the math simple and repeatable.
Worked Examples
Example 1 — 50 g of raw walnuts (default 2.61 g/100 g):
50 × (2.61 ÷ 100) = 1.31 g sugar. That is roughly a quarter of the sugar in a typical medium banana.
Example 2 — 1 cup of chopped walnuts:
The cup converts to 120 g, so 120 × (2.61 ÷ 100) = 3.13 g sugar.
Example 3 — 10 walnut kernels:
10 kernels ≈ 40 g, so 40 × (2.61 ÷ 100) = 1.04 g sugar.
Example 4 — honey-roasted walnuts with 5 g/100 g:
For a 30 g serving: 30 × (5 ÷ 100) = 1.50 g sugar — nearly double the sugar of the same weight of raw walnuts.
Reference Sugar Values
| Walnut portion | Approx. weight | Sugar (at 2.61 g/100g) |
|---|---|---|
| 1 walnut kernel | 4 g | 0.10 g |
| 10 kernel pieces | 40 g | 1.04 g |
| 30 g (about 7–8 kernels) | 30 g | 0.78 g |
| 1 oz (about 14 halves) | 28.35 g | 0.74 g |
| 1 cup chopped | 120 g | 3.13 g |
Frequently Asked Questions
Why does the calculator use 2.61 g of sugar per 100 g? That value comes from USDA FoodData Central for raw English walnuts. The sugar in walnuts is naturally occurring — not added — and includes small amounts of glucose, fructose, and sucrose. Other varieties, such as black walnuts, can have slightly different values, so check the label or a trusted nutrition database if you need a precise figure for a different type of walnut.
Are walnuts suitable for a low-carb or diabetic diet? In moderate portions, yes. At 2.61 g per 100 g, even a 30 g handful contains just 0.78 g of sugar. That same serving also provides about 2 g of fiber, which helps slow digestion and moderate blood sugar response. Still, consider total carbohydrates — not just sugar — when planning meals, and consult your healthcare provider for personalized guidance.
Tips & Best Practices
For diabetes and low-carb meal planning, raw walnuts are a smart choice: they are naturally low in sugar and provide healthy unsaturated fats, protein, and fiber. Just keep portion size in mind — nuts are calorie-dense, so a typical serving is about 30 g or a small handful.
USDA FoodData Central maintains the authoritative nutrition profile for raw English walnuts, which is the source of the 2.61 g per 100 g value used here: USDA FoodData Central — Nuts, walnuts, English.