Calorie Calculator

The activity multiplier has a larger effect on your calorie target than most people realize. Moving from "sedentary" to "moderate exercise" adds approximately 400–500 calories to a typical TDEE. Getting this wrong means your calculated target is off by that same amount — which explains why many people eat at "maintenance" and still gain weight.

Here's how to choose honestly:

• Sedentary (×1.2): Desk job, no intentional exercise, mostly sitting outside of work. This is the right choice for most office workers who don't exercise. More people belong here than want to admit it.
• Lightly active (×1.375): 1–3 days of light exercise per week, or a job with moderate standing and movement. Walking the dog daily qualifies. A 30-minute walk 3 days a week qualifies. A full day of sitting does not.
• Moderately active (×1.55): 3–5 days of genuine cardiovascular or strength training per week. This is the correct level for someone consistently hitting the gym 4 days a week, not 4 days occasionally.
• Very active (×1.725): 6–7 days of hard training, or a physically demanding job plus regular exercise. Construction workers, competitive athletes, and people doing two-a-days. Not "I go to the gym most days."

The most common mistake: Choosing "moderately active" when you exercise 2–3 times per week and sit the rest of the time. Start with the level below what feels accurate, track your weight for 2 weeks, and adjust if needed. It's far easier to add calories back than to figure out why you're not losing weight.

A 500-calorie daily deficit produces roughly 1 pound of fat loss per week in theory — the often-cited "3,500 calorie rule." In practice, the relationship is less linear (your body adapts), but it remains a useful starting framework.

What a safe deficit looks like:

• 500 calories/day (−1 lb/week): The standard recommendation. Sustainable, preserves muscle mass when combined with adequate protein and resistance training. Appropriate for most people.
• 750 calories/day (−1.5 lbs/week): Faster but manageable for those with more to lose. Protein intake becomes more important to prevent muscle loss.
• 1,000 calories/day (−2 lbs/week): The upper limit of what most guidelines consider safe for non-supervised weight loss. Only appropriate for people with BMI significantly above healthy range. Muscle loss risk increases substantially.

What's too aggressive:

Going below 1,200 calories/day (women) or 1,500 calories/day (men) is generally considered unsafe without medical supervision. Very low calorie diets trigger adaptive thermogenesis — your metabolism slows, hunger hormones increase, and the rate of fat loss plateaus while muscle loss accelerates. This is the physiological mechanism behind weight loss plateaus and why crash diets have high rebound rates.

The 3,500 calorie myth caveat: The Things Worth Knowing section below explains this well — actual weight loss typically runs 40–60% of what the arithmetic predicts due to metabolic adaptation. Adjust based on real-world results over 2–3 week periods, not daily weigh-ins.

Calories determine whether you gain, maintain, or lose weight. Macronutrient ratios determine what you gain or lose — muscle vs. fat — and how sustainable the process feels.

• Protein is the most important macro for anyone trying to lose fat without losing muscle. Aim for 0.7–1g per pound of bodyweight. Protein has the highest thermic effect of food (20–30% of its calories are burned digesting it), keeps you fullest per calorie, and is the building block for muscle retention during a deficit.
• Carbohydrates are the body's preferred fuel for exercise and brain function. They're not the enemy — the right amount depends on your activity level. Active people training 4+ days per week do better with higher carbohydrate intake (40–50% of calories). Sedentary people can tolerate lower carb ratios without performance loss.
• Fat is essential for hormone production, vitamin absorption (A, D, E, K), and satiety. Never drop below 0.3g per pound of bodyweight — going lower risks hormonal disruption and micronutrient deficiencies.

A practical starting framework for most people:

• Fat loss: 40% protein / 35% carbs / 25% fat
• Maintenance: 30% protein / 45% carbs / 25% fat
• Muscle gain: 30% protein / 50% carbs / 20% fat

For a detailed macronutrient breakdown tailored to your specific goals, see the TDEE Calculator.