How Many Calories Should You Eat to Lose Weight? A Calculator-Free Guide

There is no universal calorie number. The "1,200 calories for women, 1,800 for men" advice you see plastered across magazines is wildly off for most people — usually too low for active people, sometimes too high for sedentary ones. Below is the actual math behind a sensible weight-loss target.

Step 1: estimate your maintenance calories (TDEE)

Your Total Daily Energy Expenditure (TDEE) is the number of calories you burn in a day from everything: basic metabolism, walking around, exercise, even digesting food. Eat that exact number and your weight stays the same. Eat less and you lose; eat more and you gain.

The most reliable formula for an estimate is the Mifflin-St Jeor equation:

• Men: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
• Women: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161

That gives you your Basal Metabolic Rate — what you burn just being alive. Multiply BMR by an activity factor for TDEE:

• Sedentary (desk job, no exercise): × 1.2
• Lightly active (walking, 1–2 workouts/week): × 1.375
• Moderately active (3–5 workouts/week): × 1.55
• Very active (daily training): × 1.725

A 30-year-old woman, 168 cm, 70 kg, moderately active:

• BMR = (10 × 70) + (6.25 × 168) − (5 × 30) − 161 = 700 + 1,050 − 150 − 161 = 1,439
• TDEE = 1,439 × 1.55 = ≈ 2,230 kcal/day

That is her maintenance number — not 1,500.

Step 2: pick a deficit, not a target

The mistake most people make is choosing a calorie target like "1,500 kcal" without knowing their maintenance. Then they wonder why they are starving. Always work in deficits relative to your TDEE, not absolute numbers.

A reasonable weight-loss deficit is 300–500 calories per day below TDEE:

• 300 kcal deficit → ~0.3 kg (0.6 lb) per week — slow, sustainable, easy to stick with
• 500 kcal deficit → ~0.5 kg (1.1 lb) per week — faster but more demanding
• 750 kcal deficit → ~0.75 kg (1.6 lb) per week — only for short cuts, with high protein
• Above 1,000 kcal deficit → use sparingly, supervised, max 4–6 weeks

For our example woman: 2,230 − 400 = 1,830 kcal/day for a moderate weight-loss target. Notice how much higher this is than the generic "1,500" advice. She would lose more weight at 1,830 than at 1,500, because she could actually stick to it.

Step 3: measure your real baseline (the step everyone skips)

The Mifflin-St Jeor estimate is reliable across populations but can be off by ±15 percent for any individual. The only way to know your real number is to measure.

Track everything you eat for 7–10 days without changing your diet. Weigh yourself at the same time each morning and average the readings.

• Weight stable → your average daily intake during that week is your real maintenance
• Weight up by X kg → you ate at maintenance + about 7,700 kcal × X over the week
• Weight down by X kg → you were already in a deficit

That measured number is more useful than any equation. Then subtract 300–500 from it.

Step 4: protein is non-negotiable

Whatever your calorie target, hit at least 1.6 grams of protein per kilogram of body weight per day — closer to 2.2 g/kg if you train hard or are in a steeper deficit. Protein:

• Preserves muscle mass during weight loss (so you lose fat, not lean tissue)
• Increases satiety more than carbs or fat (you feel less hungry)
• Has the highest thermic effect — your body burns ~25 percent of protein calories just digesting it

For a 70 kg woman: 70 × 1.6 = 112 g protein/day, minimum. That is roughly 4 oz of chicken at lunch, 4 oz of fish at dinner, two eggs at breakfast, and a Greek yogurt as a snack.

Step 5: carbs and fat fill the rest

Once you have set calories and protein, the remaining calories split between carbs and fat. There is no single "best" ratio — it depends on your training type, your hormones, and what makes you feel good.

A reasonable default for the same 70 kg woman at 1,830 kcal/day:

• Protein: 112 g × 4 = 448 kcal
• Fat: ~65 g (1 g/kg) × 9 = 585 kcal
• Carbs: 1,830 − 448 − 585 = 797 kcal ÷ 4 = 199 g/day

You can shift the carb/fat balance based on preference. What you cannot shift is the protein floor.

Common mistakes

Eating below BMR. Calorie targets below your BMR (in our example, 1,439 kcal) are usually too aggressive. They suppress thyroid output, kill performance in the gym, and produce stronger hunger signals than your willpower can fight. Stay above BMR unless you are short-term cutting under supervision.

Forgetting to recalculate. As you lose weight, your TDEE drops. A woman who started at 80 kg with TDEE of 2,400 will not have the same TDEE at 70 kg. Recalculate every 5 kg of weight loss.

Confusing weekly variance with progress. Body weight fluctuates 1–2 kg from water alone. Track weekly averages, not daily numbers, and judge progress over 3–4 weeks.

Ignoring food quality. 1,830 calories of donuts technically equals 1,830 calories of salmon, vegetables, and rice. In practice, the second version produces dramatically better outcomes — more satiety, better body composition, less hunger spikes. Calorie targeting and food quality are independent levers; pull both.

The shortcut

If equations make your eyes glaze over, the simpler heuristic that works for most people:

• Sedentary office worker: 28–30 kcal × body weight in kg = maintenance
• Active person who trains 3–5x/week: 32–36 kcal × kg = maintenance
• Heavy training, daily activity: 38–42 kcal × kg = maintenance
• Subtract 300–500 from that number for a sustainable cut

A 70 kg moderately-active person: 70 × 33 = 2,310 maintenance, target ~1,900 kcal/day for weight loss. That matches the precise calculation above to within 100 calories.

What to do this week

1. Calculate your TDEE using either the formula or the rule of thumb.
2. Subtract 300–500 calories.
3. Set a protein target of ≥1.6 g/kg.
4. Track for a week — including liquids and oils.
5. After two weeks, recalibrate based on actual weight change.

The number itself matters less than the consistency. The right calorie target is the one you can hit nine days out of ten — not the lowest one a calculator will let you save.