How to Calculate Macros for Weight Loss

What Are Macros and Why Do They Matter for Fat Loss?

Macronutrients, or macros, are the three categories of nutrients that provide calories: protein, carbohydrates, and fat. Each gram of protein provides 4 calories, each gram of carbohydrate provides 4 calories, and each gram of fat provides 9 calories.

Tracking macros goes beyond simple calorie counting. Two people can eat 1,600 calories per day, but one might eat mostly carbs and very little protein while the other maintains a balanced ratio. The person with adequate protein will preserve more muscle, feel fuller, and likely see better body composition results.

Step 1: Calculate Your Calorie Needs

Before setting macros, you need to know your total daily energy expenditure (TDEE). This is the total number of calories you burn in a day including your basal metabolic rate and activity.

Quick Estimation Method

• Sedentary (desk job, little exercise): Body weight in pounds x 12-13
• Moderately active (exercise 3-4 days/week): Body weight x 14-15
• Very active (exercise 5-6 days/week, physical job): Body weight x 16-17

A 150-pound woman who exercises 3 times per week would estimate her TDEE at about 2,100 to 2,250 calories per day.

For a more precise estimate, use our BMR Calculator to find your basal metabolic rate, then multiply by your activity factor.

Setting Your Deficit

For sustainable fat loss, aim for a caloric deficit of 300 to 500 calories per day. This produces roughly 0.5 to 1 pound of fat loss per week, which is the rate most associated with preserving lean mass.

Larger deficits (more than 500 calories) increase muscle loss, spike hunger hormones, and often lead to rebound weight gain. Patience produces better long-term results than aggressive restriction.

Using the example above: 2,175 (midpoint TDEE) minus 400 = a target of about 1,775 calories per day.

Step 2: Set Your Protein Target

Protein is the most important macro to get right during fat loss. It preserves muscle mass, increases satiety, and has the highest thermic effect (your body burns more calories digesting protein than carbs or fat).

Research-backed protein recommendations for fat loss:

• General recommendation: 0.7 to 1.0 grams per pound of body weight
• Women actively strength training: 0.8 to 1.0 grams per pound
• If significantly overweight: Use goal body weight or lean body mass for the calculation instead of total weight

For a 150-pound woman: 150 x 0.8 = 120 grams of protein per day (480 calories from protein).

Step 3: Set Your Fat Target

Dietary fat is essential for hormone production, vitamin absorption, and brain function. Cutting fat too low disrupts menstrual cycles, lowers testosterone (yes, women need it too), and impairs mood.

Recommended fat intake for fat loss:

• Minimum: 0.3 grams per pound of body weight
• Recommended range: 0.3 to 0.5 grams per pound

For a 150-pound woman: 150 x 0.35 = 53 grams of fat per day (477 calories from fat).

Never go below 40 grams of fat per day regardless of body weight. Hormonal disruption from very low fat intake can stall fat loss entirely.

Step 4: Fill the Rest With Carbs

After setting protein and fat, the remaining calories come from carbohydrates. Carbs are the most flexible macro because your body can function across a wide range of carb intake.

Using our example:

1. Total calories: 1,775
2. Protein: 120g x 4 cal = 480 calories
3. Fat: 53g x 9 cal = 477 calories
4. Remaining for carbs: 1,775 – 480 – 477 = 818 calories
5. Carbs: 818 / 4 = 205 grams per day

Final macros: 120g protein / 205g carbs / 53g fat = 1,775 calories

Common Macro Ratios for Fat Loss

If the math above feels overwhelming, these simplified ratios are a reasonable starting point:

• Moderate carb (most popular): 40% carbs / 30% protein / 30% fat
• Lower carb: 25% carbs / 40% protein / 35% fat
• Higher carb (better for intense training): 50% carbs / 30% protein / 20% fat

The “best” ratio depends on your preferences, activity level, and how your body responds. There is no single optimal macro split that works for everyone. The ratio you can sustain consistently is the one that will produce results.

Meal Planning With Macros

Hitting your macro targets is easier with some structure:

Protein at Every Meal

Divide your total protein evenly across 3 to 4 meals. If your target is 120 grams, aim for 30 to 40 grams per meal. Good sources include:

• Chicken breast (31g per 4 oz)
• Greek yogurt (15-20g per cup)
• Eggs (6g each)
• Fish and shrimp (20-25g per 4 oz)
• Tofu (20g per cup)
• Lentils (18g per cup cooked)

Prioritize Whole Food Carbs

Vegetables, fruits, whole grains, potatoes, oats, and rice provide fiber and micronutrients alongside carbohydrates. These keep you fuller than refined carbs like white bread or sugary snacks.

Include Healthy Fats

Avocado, olive oil, nuts, seeds, and fatty fish provide essential fatty acids. Measure portions carefully since fat is calorie-dense. One tablespoon of olive oil is 14 grams of fat and 120 calories.

Common Mistakes to Avoid

1. Not weighing food. Eyeballing portions leads to consistent underestimation. A food scale costs $10 to $15 and eliminates guesswork.
2. Obsessing over daily perfection. Aim to hit your macros within 5 to 10 grams each day. Weekly averages matter more than any single day.
3. Cutting calories too aggressively. If you are consistently hungry, irritable, losing strength in the gym, or losing more than 1% of body weight per week, your deficit is too large.
4. Ignoring fiber. Aim for 25 to 30 grams of fiber per day from whole food sources. Fiber supports gut health and dramatically improves satiety.
5. Skipping protein on rest days. Your muscles recover and grow on rest days. Protein needs do not decrease just because you did not train.

You may also find our Body Fat Calculator and Ideal Body Weight Calculator helpful for setting realistic body composition goals.