Protein Calculator for Weight Loss
Calculate how much protein you need to preserve muscle while losing fat. Higher protein during a calorie deficit keeps you full and protects lean mass.
Why Protein Matters for Weight Loss
Preserves Muscle
During a calorie deficit, your body can break down muscle for energy. Higher protein intake (1.2–2.0 g/kg) signals your body to preserve lean tissue and prioritize fat loss instead.
Increases Satiety
Protein is the most satiating macronutrient. Eating more protein helps you feel full longer, reducing cravings and making it easier to stick to your calorie deficit.
Boosts Metabolism
Protein has the highest thermic effect of food — your body burns 20–30% of protein calories just digesting it, compared to 5–10% for carbs and 0–3% for fats.
Protein Intake During a Calorie Deficit
When eating fewer calories than you burn, your protein needs actually increase compared to maintenance. Research supports 1.2–2.0 g per kg of body weight per day during a deficit, with the higher end (1.6–2.0 g/kg) being especially beneficial if you are also resistance training.
Combining higher protein with resistance training during a calorie deficit is the most effective strategy for losing fat while maintaining (or even gaining) muscle mass — a process sometimes called body recomposition.
Weight-Loss Protein Targets by Body Weight
| Body Weight | Moderate Deficit | Training + Deficit | Aggressive Cut |
|---|---|---|---|
| 60 kg / 132 lb | 72 g | 96 g | 120 g |
| 75 kg / 165 lb | 90 g | 120 g | 150 g |
| 90 kg / 198 lb | 108 g | 144 g | 180 g |
| 105 kg / 231 lb | 126 g | 168 g | 210 g |
Moderate deficit uses 1.2 g/kg, training plus deficit uses 1.6 g/kg, and aggressive cut uses 2.0 g/kg.
How to Choose Your Target
Start near 1.2-1.6 g/kg if your calorie deficit is modest and you are not doing much strength training. This is usually enough to improve satiety while keeping meal sizes realistic.
Move toward 1.6-2.0 g/kg if you lift weights, are already lean, are losing weight quickly, or notice strength dropping during the cut. In these cases, preserving lean mass is more important than keeping protein at a minimum.
If body fat is high, entering body fat percentage in the calculator can prevent an inflated target by using an adjusted weight. That keeps the target useful without turning the diet into an unnecessarily high-protein plan.
Food and Meal Guides for Weight Loss
Formula Used for Weight-Loss Protein
The weight-loss calculator uses a higher protein range than maintenance because calorie deficits increase the risk of muscle loss and hunger.
| Input | Formula | How it is used |
|---|---|---|
| Moderate deficit | effective body weight in kg × 1.2 g/kg | Best when weight loss is slow, training volume is low, or appetite is manageable. |
| Training + deficit | effective body weight in kg × 1.6 g/kg | The default target when strength training and fat loss happen together. |
| Aggressive cut | effective body weight in kg × 2.0 g/kg | Useful when dieting quickly, already lean, or trying hard to preserve strength. |
If body fat percentage is above 30% and entered in advanced settings, the calculator uses adjusted body weight to avoid over-shooting.
Worked Example for Weight Loss
For a 90 kg person cutting calories while lifting:
- 1. Moderate target: 90 kg × 1.2 g/kg = 108 g/day.
- 2. Training target: 90 kg × 1.6 g/kg = 144 g/day.
- 3. Aggressive cut target: 90 kg × 2.0 g/kg = 180 g/day.
- 4. Across four meals, 144 g/day is about 36 g per meal.
A practical starting target is 140-160 g/day, then adjust if hunger, recovery, or adherence suffers.
When to Use This Calculator
Matching Guides
Sources reviewed
- International Society of Sports Nutrition Position Stand: diets and body composition - Journal of the International Society of Sports Nutrition / PMC
- International Society of Sports Nutrition Position Stand: protein and exercise - Journal of the International Society of Sports Nutrition
- Dietary Reference Intakes summary tables - National Academies Press
Frequently Asked Questions
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Learn More
Why higher protein during a calorie deficit preserves lean mass, increases satiety, and supports sustainable fat loss.
Foods ranked by protein per calorie for fat loss and lean meals.
Meal templates, recipes, and product shortcuts for dieting.
Body-composition guidance for preserving muscle while cutting.