Kidneys are one of the most nutrient-dense organ meats, packed with protein, B vitamins, and essential minerals — but they also contain a measurable amount of fat. Whether you're tracking macros, following a keto or carnivore diet, or simply exploring organ meats, knowing the fat content per 100 g makes portion planning much easier.
This calculator estimates fat for beef, pork, lamb, and chicken kidneys in both raw and cooked forms. Enter a serving in grams, ounces, or pounds, and you'll instantly see fat per 100 g, total fat, saturated fat, calories from fat, total calories, and protein for your exact portion. You can also check what percentage of calories comes from fat.
Use the quick-fill buttons for common serving sizes, or switch on advanced mode to enter a custom fat value from your own product label. The step-by-step breakdown shows exactly how each number is calculated, so you can verify the math or adjust it for a specific recipe.
How to Use This Tool
Select the kidney type (beef, pork, lamb, or chicken) and the preparation (raw or cooked), then enter a serving size in grams, ounces, or pounds. Click Calculate to see fat per 100 g, total fat, saturated fat, calories from fat, total calories, and protein for your exact portion. The preset buttons (100 g, 3 oz, 4 oz) are handy for common servings. If you have a package label with a different fat value, switch on Advanced mode and enter your own fat per 100 g.
Tip: Weigh kidneys raw before cooking if you plan to use raw values. If you weigh a cooked portion, choose the cooked preparation to get the most accurate estimate.
Formula Explained
This calculator works by scaling reference values per 100 g to your portion size. First it converts your serving to grams (1 oz = 28.35 g, 1 lb = 453.59 g). Then it applies a simple proportion:
Total fat (g) = fat per 100 g × (serving weight in g ÷ 100)
Calories from fat = total fat × 9 kcal/g. The share of calories from fat is then (calories from fat ÷ total calories) × 100. Saturated fat is estimated by multiplying total fat by a typical fatty-acid factor for that animal.
This method assumes the reference values are representative. Individual kidneys vary with the animal's diet, age, and how much connective tissue remains attached, so treat results as a useful estimate rather than a lab measurement.
Worked Examples
Example 1 – Beef kidney, cooked, 150 g: fat per 100 g = 5.4 g, so 150 g contains 5.4 × 1.5 = 8.1 g fat. Calories from fat = 8.1 × 9 ≈ 73 kcal. Total calories ≈ 157 × 1.5 = 236 kcal, so about 31% of calories come from fat. Protein ≈ 27.3 × 1.5 = 41.0 g.
Example 2 – Pork kidney, raw, 4 oz (113 g): 113 g = 1.13 × 100 g. Fat per 100 g = 3.3 g, so total fat = 3.3 × 1.13 = 3.7 g. Protein = 16.5 × 1.13 = 18.6 g. Total calories = 100 × 1.13 = 113 kcal, with about 33 kcal from fat.
Reference Data
The table shows approximate values per 100 g based on standard USDA nutrient data for raw and simmered/braised kidneys.
| Type | Preparation | Fat (g) | Protein (g) | Calories | Saturated fat factor |
|---|---|---|---|---|---|
| Beef | Raw | 2.6 | 17.4 | 99 | 0.54 |
| Beef | Cooked | 5.4 | 27.3 | 157 | 0.54 |
| Pork | Raw | 3.3 | 16.5 | 100 | 0.40 |
| Pork | Cooked | 5.3 | 25.7 | 151 | 0.40 |
| Lamb | Raw | 2.6 | 17.1 | 97 | 0.45 |
| Lamb | Cooked | 4.6 | 24.2 | 137 | 0.45 |
| Chicken | Raw | 3.1 | 17.4 | 100 | 0.30 |
| Chicken | Cooked | 5.2 | 26.2 | 154 | 0.30 |
Raw values are from USDA FoodData Central (fdc.nal.usda.gov); cooked values refer to simmered kidneys. Saturated fat factors are typical shares of total fat for each animal and will vary slightly between cuts and producers.
Factors Affecting Accuracy
Kidneys are naturally low in fat compared with muscle meat, but exact numbers depend on the animal's diet, age, breed, and whether visible fat was trimmed before cooking. Cooking method also matters: braising in butter or oil adds fat, while simmering in water or broth mainly removes water and concentrates nutrients. If you follow a strict macro plan, use the custom fat field with a value from your own product label or a trusted database.
Frequently Asked Questions
Are kidneys a low-fat food? Yes, raw kidneys generally contain between 2.5 and 3.5 g fat per 100 g, which is lower than most cuts of muscle meat. Cooked kidneys are higher on a per-100 g basis mainly because water is lost during cooking.
Why does cooked kidney show more fat per 100 g? Cooking removes water, so the same nutrients and fat are packed into a smaller weight. Per 100 g, fat, protein, and calories all appear higher even though the total fat in the whole piece hasn't changed much.
What is a normal serving of kidney? A typical serving is about 100–150 g, similar to other meats. The NHS and many dietary guidelines recommend eating red meat in moderation, so enjoy kidneys as part of a varied diet. For authoritative nutrient data, see USDA FoodData Central.