Nat Usa Calories Calculator

How to Use This Calculator

Using the NAT USA Calories Calculator is simple. Follow these steps:

1. Enter your age in years.
2. Select your gender (male or female).
3. Enter your weight in pounds.
4. Enter your height in inches.
5. Select your activity level from the dropdown menu.
6. Click the "Calculate" button to get your results.

The calculator will display your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE) based on your inputs. The BMR represents the number of calories your body needs to perform basic functions at rest, while the TDEE accounts for your activity level.

Formula Used

The NAT USA Calories Calculator uses the Mifflin-St Jeor equation to calculate your BMR and TDEE. The formulas are as follows:

After calculating the BMR, the TDEE is determined by multiplying the BMR by an activity factor:

The activity factors are as follows:

• Sedentary (little or no exercise): 1.2
• Lightly active (light exercise/sports 1-3 days/week): 1.375
• Moderately active (moderate exercise/sports 3-5 days/week): 1.55
• Very active (hard exercise/sports 6-7 days a week): 1.725
• Extra active (very hard exercise/physical job & exercise 2x/day): 1.9

Interpreting Your Results

Understanding your BMR and TDEE can help you make informed decisions about your diet and exercise. Here's what each number means:

• BMR: This is the minimum number of calories your body needs to maintain basic functions while at complete rest. It represents the energy required to keep your organs functioning and to maintain body temperature.
• TDEE: This is the total number of calories your body needs to maintain your current weight, accounting for your activity level. It's calculated by multiplying your BMR by an activity factor.

If you want to lose weight, you should consume fewer calories than your TDEE. If you want to maintain your weight, you should consume calories equal to your TDEE. If you want to gain weight, you should consume more calories than your TDEE.

Worked Examples

Let's look at two examples to see how the calculator works in practice.

Example 1: Sedentary 30-Year-Old Male

Inputs:

• Age: 30
• Gender: Male
• Weight: 180 pounds
• Height: 70 inches
• Activity Level: Sedentary

Calculations:

1. Convert weight to kg: 180 × 0.453592 = 81.6467 kg
2. Convert height to cm: 70 × 2.54 = 177.8 cm
3. Calculate BMR: (10 × 81.6467) + (6.25 × 177.8) - (5 × 30) + 5 = 1632.93 + 1111.25 - 150 + 5 = 1599.18 kcal/day
4. Calculate TDEE: 1599.18 × 1.2 = 1919.02 kcal/day

Results:

• BMR: 1,599 kcal/day
• TDEE: 1,919 kcal/day

Example 2: Very Active 25-Year-Old Female

Inputs:

• Age: 25
• Gender: Female
• Weight: 140 pounds
• Height: 65 inches
• Activity Level: Very Active

Calculations:

1. Convert weight to kg: 140 × 0.453592 = 63.5028 kg
2. Convert height to cm: 65 × 2.54 = 165.1 cm
3. Calculate BMR: (10 × 63.5028) + (6.25 × 165.1) - (5 × 25) - 161 = 635.028 + 1038.125 - 125 - 161 = 1387.153 kcal/day
4. Calculate TDEE: 1387.153 × 1.725 ≈ 2397.8 kcal/day

Results:

• BMR: 1,387 kcal/day
• TDEE: 2,398 kcal/day