How to Calculate Your Calorie Deficit

How to Calculate Your Calorie Deficit

To calculate your calorie deficit, first determine your Total Daily Energy Expenditure (TDEE) — the number of calories your body burns in a day — and then subtract a specific amount to create the shortfall your body must fill from stored energy. The deficit is the engine of weight loss, and getting it right means balancing enough intake to sustain metabolism with enough restriction to drive fat loss.

Step 1: Estimate Your Basal Metabolic Rate

Your BMR is the energy your body uses at rest for basic functions like breathing and maintaining body temperature. The Mifflin-St Jeor equation is widely considered the most accurate for general use. For men: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age in years) + 5. For women: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age in years) − 161. If you prefer simpler math, multiplying your body weight in pounds by 10 provides a rough BMR benchmark.

Step 2: Apply an Activity Multiplier to Find TDEE

Next, multiply your BMR by an activity factor to get your TDEE. The standard multipliers are:

• Sedentary (little or no exercise): BMR × 1.2
• Lightly active (1–3 days/week of light exercise): BMR × 1.375
• Moderately active (3–5 days/week of moderate exercise): BMR × 1.55
• Very active (6–7 days/week of hard exercise): BMR × 1.725
• Extra active (very hard exercise, physical job, or training twice per day): BMR × 1.9

Step 3: Set Your Deficit

Subtract your target deficit calories from your TDEE. A 500-calorie daily deficit is the traditional recommendation, typically yielding a loss of about 1 pound (0.45 kg) of fat per week, since 1 pound of fat is roughly equivalent to 3,500 calories. A 250-calorie deficit is a more conservative approach that may be easier to sustain and preserves more muscle mass when paired with resistance training and adequate protein intake.

Step 4: Track and Adjust

Use a food scale and a tracking app to log intake accurately, and weigh yourself consistently under the same conditions each morning. If your weight stalls for two weeks, reduce intake by 100 to 150 calories or add a few more minutes of daily movement. Recalculate your TDEE whenever your weight changes by more than 10 pounds, as your energy needs will have shifted.

What a Safe Deficit Looks Like

A deficit of 10–20% below your TDEE is generally considered safe for most people. For example, if your TDEE is 2,200 calories, a 220- to 440-calorie deficit falls within that range. Deficits exceeding 25% of TDEE increase the risk of nutrient deficiency, muscle loss, hormonal disruption, and metabolic adaptation.