It's the starting question for any weight loss: how many calories should you eat per day to lose weight? The answer isn't a single number, but it can be calculated. It all comes down to a simple concept: the caloric deficit, meaning consuming slightly less than what your body burns.
To spare you complicated formulas, we've integrated a calculator directly into this article: it estimates your daily needs and proposes an appropriate deficit goal for you. Then we explain how to read your results, which deficit to choose, and how to apply it healthily, without falling into the trap of "always less."
The hardest part of a caloric deficit is sticking with it without giving in. As a complement to controlled eating, ActifMinceur® supports your journey. A tool, never a substitute for calculation or balanced nutrition.
To lose weight, you need a caloric deficit : eat less than what you burn. The method: calculate your maintenance needs (basal metabolism × activity level), then subtract a deficit. A moderate deficit (-20%) is the best compromise: noticeable yet sustainable, it preserves muscle. Expect approximately 0.5 kg per week for a healthy pace. Never drop below 1,200 kcal (women) or 1,500 kcal (men) without medical advice. The calculator below gives you your personalized estimate, for informational purposes.
1. Calculate Your Calories to Lose Weight
Calculate Your Calories to Lose Weight
Estimate your daily requirement and deficit for reference purposes.
2. The Principle: Losing Weight Is About Calorie Deficit
Regardless of the latest diet trend, they all work through the same mechanism: calorie deficit. Whether you eat less, eat healthier, or move more, the result is the same: you create a gap between what you consume and what you burn, and your body fills this gap by drawing from its fat reserves.
To manage this deficit, two numbers matter. First, your basal metabolic rate : the calories your body burns at rest, just to live (breathing, heart, brain). It represents the majority of your expenditure. Then comes the maintenance need : your basal metabolism plus your physical activity. It's the number of calories that keeps you from gaining or losing weight. To lose weight, you eat slightly below this maintenance need.
3. How to read your result
Your result first displays your maintenance need : eat at this level and your weight stays stable. Below it, you'll find three deficit scenarios. The mild deficit (-10%) is suitable for very gentle loss or to start comfortably. The moderate deficit (-20%), highlighted, is the best results-to-sustainability ratio for most people. The aggressive deficit (-25%) speeds things up a bit, but becomes more demanding to sustain.
The estimated weekly loss is based on a simple benchmark: approximately 7,700 kcal correspond to one kilogram of fat. A deficit of 500 kcal per day therefore theoretically generates a loss of about 0.5 kg per week. This is an estimate: actual loss varies based on your body, your body water, and time. If your calculation reveals a safety floor, don't try to go below it: it's the threshold below which a diet becomes inadvisable without professional supervision.
4. Which deficit to choose?
Mild deficit (-10%)
To start or refine comfortably.
Very sustainable, almost painless day-to-day. Ideal if you're starting from further away, if you have little to lose, or if you want to build the habit without frustration. Slow but steady loss.
Moderate deficit (-20%)
The best compromise for most people.
Marked enough for visible results (often around 0.5 kg/week), gentle enough to maintain for several months and preserve muscle. This is the default recommended choice.
Aggressive deficit (-25%)
Faster, but harder to maintain.
For those who want to accelerate and feel capable of sustaining it. Requires more discipline, more protein, and good sleep. Avoid over long periods or if hunger becomes unmanageable.
5. Protein: the habit that changes everything
Once your calorie number is defined, their distribution account. And the nutrient that changes everything is protein.
Compared to standard low-calorie diets, higher-protein low-calorie diets improve weight and fat loss, and better preserve muscle mass.
According to PubMed, Wycherley TP et al. 2012, American Journal of Clinical Nutrition (meta-analysis of 24 randomized controlled trials). DOI: 10.3945/ajcn.112.044321
In practice: in a deficit, prioritize proteins (lean meat, fish, eggs, legumes, dairy products, or a protein supplement) helps you on two fronts. They satisfy, so you maintain your deficit without fighting hunger, and they protect muscle, so the weight you lose is mainly fat. For satiety, fiber also plays a role: a konjac or a psyllium before meals can help you eat less. And to structure your protein intake, see our protein balls.
6. Mistakes to avoid
The first mistake, and the most common one, is to cut too much. Out of impatience, you drastically slash calories. Result: constant hunger, fatigue, muscle loss, and giving up after two weeks. A moderate deficit maintained for three months always beats an extreme deficit maintained for ten days.
The second is to miscalculate your intake : cooking oils, beverages, forgotten snacking, underestimated portions. The calculation gives you a target, but you still have to actually stick to it. Keeping a food diary for a few days is very enlightening to start. Finally, don't neglect the rest : sleep (poor sleep sabotages appetite and food choices) and activity, which increases your expenditure. To learn more, see our guide on how to lose weight in one month, our 27 proven tips, and how much to walk to lose weight.
Frequently asked questions
How many calories per day to lose weight?
It depends on your metabolism, which varies by sex, age, weight, height, and activity level. The principle: first calculate your maintenance needs, then subtract a deficit. A moderate deficit of around 20% is a good starting point: for someone whose maintenance is 2,200 kcal, that gives about 1,760 kcal per day. Use our calculator for your personalized estimate. These values are indicative and do not replace the advice of a healthcare professional.
How many calories to lose 1 kg?
It's estimated that one kilogram of fat equals approximately 7,700 kcal. To lose about 1 kg in one week, you would need a deficit of about 1,100 kcal per day, which is often too aggressive. A more realistic and sustainable pace is to aim for 0.5 kg per week, or a deficit of about 500 kcal per day. Slower weight loss better preserves muscle and is more sustainable over time.
What caloric deficit should you choose to lose weight?
A moderate deficit, around 15 to 20% of your maintenance needs, is generally the best compromise: substantial enough for visible results, gentle enough to be sustainable and preserve muscle. Very large deficits result in faster initial weight loss, but are hard to maintain, increase muscle loss and fatigue, and promote weight regain. Consistency beats severity.
Can you go below 1,200 calories per day?
It is generally not recommended to go below approximately 1,200 kcal per day for women and 1,500 kcal for men without medical supervision. Below these levels, it becomes difficult to meet your nutrient needs, metabolism can slow down, and health risks increase. Eating very little is often counterproductive. If your calculations show values below these recommendations, consult a doctor or registered dietitian-nutritionist.
How to calculate your calories to lose weight?
We use a formula that estimates basal metabolism, such as the Mifflin-St Jeor equation, considered the most reliable according to a systematic review (Frankenfield 2005). This metabolism is multiplied by an activity factor to obtain maintenance needs, then a deficit is applied. Our calculator does this calculation for you based on your sex, age, weight, height, and activity level.
Do you need to count calories to lose weight?
Counting calories is not mandatory, but knowing your approximate range helps greatly at first to become aware of portions. Many people lose weight without weighing everything, simply by improving their diet quality, increasing protein intake, and being more active. Calculation is a useful reference point, not a lifetime obligation.
- Caloric deficit
- The difference between calories burned and consumed: a necessary condition for weight loss.
- Basal metabolism
- Calories burned at rest for vital functions. The largest part of daily energy expenditure.
- Maintenance needs
- Basal metabolism multiplied by activity level: the caloric level that maintains stable weight.
- Mifflin-St Jeor equation
- Formula for estimating basal metabolism, considered the most reliable by research.
- Activity factor
- Coefficient (from 1.2 to 1.9) applied to basal metabolism according to physical activity level.
Information from PubMed. The data describe the state of research and do not constitute health claims attributed to a product.
- Frankenfield D, Roth-Yousey L, Compher C. Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults: a systematic review. J Am Diet Assoc 2005;105(5):775-89. DOI: 10.1016/j.jada.2005.02.005
- Wycherley TP, Moran LJ, Clifton PM, Noakes M, Brinkworth GD. Effects of energy-restricted high-protein, low-fat compared with standard-protein, low-fat diets: a meta-analysis of RCTs. Am J Clin Nutr 2012;96(6):1281-98. DOI: 10.3945/ajcn.112.044321
