Fat Content Calculator Formula

Understand the math behind the fat content calculator. Each variable explained with a worked example.

Formulas Used

Total Fat

fat_g = food_weight_g * fat_pct / 100

Calories from Fat

cal_from_fat = (food_weight_g * fat_pct / 100) * 9

% of 65 g Daily Value

pct_daily_65g = (food_weight_g * fat_pct / 100) / 65 * 100

Variables

VariableDescriptionDefault
food_weight_gFood Weight(g)100
fat_pctFat Content15

How It Works

How to Calculate Fat Content

Formula

Fat (g) = Food Weight (g) x Fat Percentage / 100

Calories from Fat = Fat (g) x 9

Fat provides 9 calories per gram, more than double protein or carbs (4 cal/g each).

Daily Value

The daily value for total fat is 65 g based on a 2000 calorie diet (about 30% of calories from fat).

Worked Example

Calculate fat in 100 g of 85% lean ground beef.

food_weight_g = 100fat_pct = 15
  1. 01Fat content: 15% (85% lean = 15% fat).
  2. 02Fat: 100 x 15/100 = 15 g.
  3. 03Calories from fat: 15 x 9 = 135 kcal.

Frequently Asked Questions

What types of fat are there?

Saturated (solid at room temperature), monounsaturated (olive oil), polyunsaturated (fish oil, flax), and trans fats (partially hydrogenated oils). Unsaturated fats are generally healthier.

How much fat per day?

The USDA recommends 20-35% of daily calories from fat. On a 2000 kcal diet, that is 44-78 g of fat per day.

Does cooking add fat?

Frying adds fat from the cooking oil. Grilling and baking can reduce fat as it drips away. The cooking method significantly affects total fat content.

Ready to run the numbers?

Open Fat Content Calculator