Calorie Calculator - Daily Calorie Needs & Macro Split
Find your maintenance calories and a daily target for losing or gaining weight, with a protein, carbohydrate and fat breakdown — and a warning if the target goes too low.
Macronutrient split
Calories for every goal
| Goal | Daily calories | Change vs maintenance |
|---|---|---|
| Lose 1 kg per week | 1,305 ⚠️ | -1,100 |
| Lose 0.75 kg per week | 1,580 | -825 |
| Lose 0.5 kg per week | 1,855 | -550 |
| Lose 0.25 kg per week | 2,130 | -275 |
| Maintain my weight | 2,405 | +0 |
| Gain 0.25 kg per week | 2,680 | +275 |
| Gain 0.5 kg per week | 2,955 | +550 |
Calorie needs are estimates based on population averages. Weight change also depends on food quality, sleep, medication, hormones and how accurately intake is tracked. This tool is for general information and is not medical or dietary advice — consult a qualified professional before making significant changes, especially if you are pregnant, breastfeeding, under 18 or managing a medical condition.
What is a Calorie Calculator?
A calorie calculator estimates how much energy you burn in a day and turns that into a daily intake target for your goal. It starts from your basal metabolic rate using the Mifflin-St Jeor equation, multiplies by an activity factor to get total daily energy expenditure, then adds or subtracts an amount matched to the rate of weight change you want.
How Big Should a Calorie Deficit Be?
A kilogram of body fat stores roughly 7,700 calories. Divide across a week and a deficit of about 1,100 calories a day corresponds to 1 kg of loss, 550 to half a kilogram, and 275 to a quarter. Most guidelines consider 0.5–1% of body weight per week a sustainable rate; faster than that and you lose proportionally more muscle, feel worse, and are far more likely to abandon the attempt.
- Maintenance calories (TDEE) calculated from your own body details
- Targets for four rates of loss and two rates of gain
- Automatic warning when a target drops below a safe floor
- Macronutrient breakdown in grams for three different splits
- Protein shown per kilogram of body weight
- Metric and imperial units
Understanding Macronutrients
Protein — 4 kcal/g
Preserves muscle in a deficit and is the most filling macronutrient. 1.2–2.0 g per kg is the usual guidance.
Carbohydrates — 4 kcal/g
The main fuel for training. Higher intakes suit endurance and high-volume work.
Fat — 9 kcal/g
Essential for hormone production and absorbing vitamins A, D, E and K. Rarely worth taking very low.
How to Use the Calculator
- Choose metric or imperial units.
- Enter your sex, age, height and weight.
- Select the activity level that honestly matches your week.
- Pick your goal — maintain, lose, or gain at a chosen rate.
- Read your daily calorie target and macro grams.
- Compare every goal in the table at the bottom.
Minimum Safe Intake
Widely used clinical floors are around 1,500 calories a day for men and 1,200 for women. Below those levels it becomes difficult to meet micronutrient needs, muscle loss accelerates, and the approach normally requires medical supervision. The calculator flags any target that falls below this threshold rather than quietly presenting it as a plan — if you see the warning, choose a slower rate of loss or raise your activity level instead of cutting further.
Why Weight Loss Stalls
A calorie target is a model, and models drift from reality for predictable reasons:
- Under-reporting intake — the most common cause by a wide margin. Cooking oils, drinks and untracked bites add up quickly.
- Reduced spontaneous movement — in a deficit people unconsciously move less, shrinking the activity component of TDEE.
- Metabolic adaptation — a smaller body needs fewer calories, so the original deficit narrows as you lose weight. Recalculate every few kilograms.
- Water retention — glycogen, sodium, hormonal cycles and training soreness can hide real fat loss for weeks on the scale.
The practical answer is patience with data: hold a target for two to three weeks, use a weekly average weight rather than a single reading, and only then adjust.
Does the Macro Split Matter?
Far less than total calories. For weight change, the calorie total does nearly all the work. Where the split matters is adherence, training performance and body composition: adequate protein protects muscle in a deficit and keeps you fuller, while carbohydrate intake affects how good your training feels. Choose the split you can actually sustain — the best diet composition is the one you will still be following in six months.
Who This Calculator Is For
- Anyone starting a weight loss or weight gain plan
- People tracking macros for the first time
- Gym-goers eating for muscle gain
- Athletes matching intake to training load
- Coaches setting client calorie baselines
- Anyone who wants a maintenance figure to eat around
❓ Frequently Asked Questions
How many calories should I eat a day?
Start from your TDEE — the calories you burn on an average day. Eat at that level to maintain weight, below it to lose and above it to gain. The calculator works out all three from your body details and activity level.
How big should a calorie deficit be?
A deficit of 500–550 calories a day corresponds to roughly 0.5 kg of fat loss per week, which most guidelines consider a sustainable rate. Larger deficits increase muscle loss and are harder to maintain.
How many calories are in a kilogram of body fat?
Roughly 7,700 calories, which is why a 1,100 calorie daily deficit is needed for about 1 kg of loss per week. Real-world results vary because the body adapts.
What is the minimum safe calorie intake?
Widely used floors are about 1,500 calories a day for men and 1,200 for women. Going lower risks nutrient deficiencies and muscle loss and should only be done under medical supervision — the calculator warns you when a target falls below this.
What are macros?
Macronutrients are protein, carbohydrates and fat. Protein and carbohydrates supply 4 calories per gram and fat supplies 9, which is how the calculator converts your calorie target into grams.
How much protein do I need?
General guidance is 1.2–2.0 g per kilogram of body weight, with the upper end useful when losing weight or building muscle. The calculator shows your protein in grams per kilogram so you can check.
Which macro split is best?
Total calories drive weight change far more than the split does. Choose the split you can stick to: balanced suits most people, lower carb suits those who prefer fats and protein, higher carb suits endurance training.
Why am I not losing weight in a deficit?
The most common reasons are underestimating intake, reduced spontaneous movement, water retention masking fat loss, and metabolic adaptation. Track for two to three weeks before adjusting.
Do I need to eat fewer calories on rest days?
Not necessarily. Most people find it simpler to use one daily average target, since weight change depends on the weekly total rather than any single day.
Is this medical or dietary advice?
No. These are estimates for general information. Speak to a doctor or registered dietitian before making significant dietary changes, especially if you are pregnant, breastfeeding, under 18 or managing a medical condition.