The answer is different for every person — and guessing it is the #1 reason most diets fail. Before counting a single calorie, you need one number: your Total Daily Energy Expenditure (TDEE). That’s the exact calories your body burns each day. Eat below it and you lose weight. Eat above it and you gain. Everything else is noise.
What is TDEE and why does it matter?
Your TDEE is the total calories your body burns in a 24-hour period — not just at rest, but including every step you take, every workout you do, and even the energy used to digest food. It’s calculated from your Basal Metabolic Rate (BMR) — the calories your body needs at complete rest — multiplied by your activity level.
Most people try to lose weight by cutting food randomly — removing carbs, skipping meals, eating “clean” — without ever knowing how many calories they actually burn. Without your TDEE, you’re guessing. And guessing is why most diets stall within 3 weeks.
Example: Two people who both weigh 70kg can have TDEEs of 1,800 and 2,400 calories — a 600 calorie difference — depending on age, height, gender and activity level. The same diet would produce completely different results for each of them.
This is why generic calorie recommendations like “eat 1,200 calories” are not just unhelpful — they can be actively harmful. Your number is personal to your body.
How many calories should I eat to lose weight?
To lose weight, you need to eat fewer calories than your TDEE. The difference between what you burn and what you eat is called your calorie deficit. Your body makes up that energy gap by burning stored fat.
For most people, a deficit of 400–500 calories per day produces approximately 0.5 kg of fat loss per week — a rate that is safe, sustainable, and preserves muscle mass. Here’s how that looks across different goals:
Calculate your TDEE now
Enter your age, weight, height and activity level — your personal daily calorie target appears in 30 seconds.
Calculate My TDEE →How big should my calorie deficit be?
The most common mistake is making the deficit too large too fast. A deficit of 1,000+ calories per day might seem like it would double your results — but research consistently shows it leads to muscle loss, extreme hunger, metabolic adaptation, and eventual rebound weight gain.
The sweet spot for most people is a deficit of 400–500 kcal/day. Here’s why this works better than extremes:
Preserves muscle — high protein + moderate deficit keeps muscle while burning fat, rather than burning both equally
Sustainable hunger levels — you’re not constantly starving, so compliance is dramatically higher over weeks and months
Protects metabolism — very low calorie diets slow your metabolism as your body adapts to conserve energy, stalling progress
Important: Never eat below your BMR (Basal Metabolic Rate) — the calories your body needs at complete rest to keep organs functioning. Doing so consistently is dangerous and counterproductive. Use our free BMR calculator to find your floor.
Why am I not losing weight even in a calorie deficit?
This is one of the most common frustrations in weight loss — and the answer is almost always the same. Studies consistently show that people underestimate their calorie intake by 20–40% when estimating portion sizes and tracking manually.
A handful of almonds you log as “small” might be 200 calories. A restaurant portion of rice could be double what you tracked. Cooking oil you didn’t log adds 120 calories. These gaps add up to hundreds of calories a day — completely erasing your deficit without you realising.
Frequently asked questions
How do I calculate how many calories I need to lose weight?
First calculate your TDEE — the calories your body burns each day. Then subtract 400–500 calories from that number. The result is your daily calorie target for weight loss. Use our free TDEE calculator to get your personal number in 30 seconds.
Is 1,200 calories a day enough to lose weight?
1,200 calories is not a universal target — it may be appropriate for some people but dangerously low for others. Whether 1,200 calories creates a healthy deficit depends entirely on your personal TDEE. Someone with a TDEE of 1,600 kcal would have a reasonable 400 kcal deficit. Someone with a TDEE of 2,400 kcal would be creating a dangerous 1,200 kcal deficit. Always base your intake on your individual TDEE.
How long will it take to lose 5kg eating in a calorie deficit?
At a moderate deficit of 500 kcal/day, you will lose approximately 0.5 kg per week. At that rate, losing 5kg takes about 10 weeks. A larger deficit of 750 kcal/day would get you there in roughly 7 weeks, but comes with more hunger and slightly higher risk of muscle loss. Use our calorie deficit calculator to see your personal timeline.
Should I eat back calories burned during exercise?
It depends on how you calculated your TDEE. If you used a moderate or active activity multiplier, your exercise calories are already included in your TDEE — so eating them back would cancel your deficit. If you used “sedentary” as your activity level and exercise regularly, eating back a portion (around 50%) of burned calories is reasonable to prevent excessive hunger and muscle loss.
What is the best app to track calories for weight loss?
The best calorie tracker is one you’ll actually stick to. Traditional apps require manual logging which most people abandon within 2 weeks because it’s too tedious. Tou Calo uses AI to identify food from a photo and log calories in 3 seconds — removing the friction that causes people to give up. It also tracks protein, carbs and fat automatically so you never have to search a database again.
The next step is tracking meals accurately — every single day.
Tou Calo makes this effortless. Snap any food — AI logs it in 3 seconds. No manual entry, no guessing, no giving up after a week.
The team behind Tou Calo AI Calorie Counter. We build tools that make healthy eating effortless — starting with understanding your personal calorie needs.