Fat Intake Calculator

How Does the Fat Intake Calculator Work?

This calculator uses the Mifflin-St Jeor equation to estimate your Basal Metabolic Rate (BMR), then multiplies it by an activity factor to obtain your Total Daily Energy Expenditure (TDEE). Fat intake is then calculated as a percentage of your TDEE.

Mifflin-St Jeor Equation

• Men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161 + 166
• Women: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161

Or more precisely:

• Men: BMR = 10w + 6.25h − 5a + 5
• Women: BMR = 10w + 6.25h − 5a − 161

Activity Multipliers

• Sedentary: ×1.2
• Lightly active: ×1.375
• Moderately active: ×1.55
• Very active: ×1.725
• Extra active: ×1.9

How Much Fat Should I Eat per Day?

The Dietary Guidelines for Americans (2020–2025) recommend that fat should constitute 20–35% of your total daily caloric intake. Since 1 gram of fat provides 9 calories, the formula is:

Daily fat (g) = (TDEE × percentage) / 9

Additionally, saturated fat should be limited to less than 10% of total calories.

Types of Dietary Fat

Unsaturated Fats (Healthy Fats)

• Monounsaturated fats — Found in olive oil, avocados, nuts. Help reduce LDL cholesterol.
• Polyunsaturated fats — Include omega-3 and omega-6 fatty acids. Found in fish, flaxseeds, walnuts.

Saturated Fats

Found in red meat, butter, cheese, and coconut oil. Excessive intake is linked to increased LDL cholesterol and cardiovascular risk. Limit to less than 10% of total calories.

Trans Fats

Artificially produced trans fats (partially hydrogenated oils) are the most harmful type. They raise LDL cholesterol while lowering HDL cholesterol. The FDA has banned artificial trans fats in food products.

Why Fats Are Important

Despite their reputation, dietary fats are essential for:

• Absorbing fat-soluble vitamins (A, D, E, K)
• Providing essential fatty acids the body cannot produce
• Building cell membranes and nerve sheaths
• Maintaining healthy skin and hair
• Producing hormones
• Providing long-lasting energy