Calorie Calculator for Weight Loss

Losing weight comes down to one thing: eating fewer calories than you burn, day after day, for long enough. The hard part is knowing how many fewer. Cut too little and nothing changes; cut too much and you feel terrible, lose muscle, and give up within a fortnight. A calorie calculator for weight loss finds the middle ground — your maintenance calories minus a deficit you can actually live with.

This page shows you how the calculator works out your target, how big your deficit should be, how fast you can expect to lose weight, and how to build meals around the number so you stay full. Try the calculator above first, then read on to understand the number it gives you.

How a Weight-Loss Calorie Target Is Calculated

The calculation has three steps. First, your BMR is worked out with the Mifflin-St Jeor equation from your sex, age, weight and height. Second, your BMR is multiplied by an activity factor to get your maintenance calories — the amount that keeps your weight exactly stable. Third, a deficit is subtracted. That final number is your daily target, and the calculator shows it in the green box at the top of your result.

Step 1 — Find Maintenance

Maintenance is the anchor for everything else. For a 30-year-old man at 70 kg and 175 cm, BMR is 1,649 calories; at moderate activity (× 1.55) maintenance is 2,556 calories a day. For a 25-year-old woman at 60 kg and 165 cm, BMR is 1,345 and maintenance at light activity (× 1.375) is 1,850 calories a day. If you do not know your maintenance, use the TDEE calculator to work it out before choosing a deficit.

Step 2 — Choose Your Deficit

A kilogram of body fat stores roughly 7,700 calories. Divide that by seven days and a 500-calorie daily deficit removes about 0.45 kg a week; a 1,000-calorie deficit removes about 0.9 kg a week. Bigger is not better — deficits over 750 a day are hard to sustain, raise hunger sharply, and cost more muscle. Most people do best starting at 500 a day, or 250 if they are already fairly lean.

Worked Example: Losing Weight at 2,056 Calories

Take the 30-year-old man from the example above. His maintenance is 2,556 calories. With the weight-loss goal selected, the calculator subtracts 500 and gives a target of 2,056 calories a day. Over a week that is 14,392 calories, a deficit of 3,500 against maintenance — about 0.5 kg of fat loss a week. At that pace he loses 2 kg in a month and 6 kg in three months, without ever feeling starved.

Notice the protein column. At 2,056 calories the balanced split gives 154 g of protein a day, which is 2.2 g per kg for a 70 kg man — plenty to protect muscle while dieting. If protein drops too low, the weight you lose is more likely to be muscle than fat. If you train, consider switching the calculator to the high-protein split, which raises protein to 40% of calories.

Why 500 Calories Is the Standard Deficit

A 500-calorie deficit is the most widely recommended starting point for three reasons. First, it produces visible progress — about 0.5 kg a week — fast enough to stay motivated. Second, it is small enough that you can achieve it by changing a few habits rather than overhauling your whole life: a smaller portion at dinner, no sugary drink, a 30-minute walk. Third, it keeps your intake high enough to cover protein and micronutrient needs. The calorie calculator lists targets for every deficit size, so you can compare 250, 500 and 1,000 side by side before deciding.

What to Eat at Your Target

A calorie target only works if you can stick to it, and staying full is the whole game. The same 2,056 calories can feel like a feast or a famine depending on what you eat.

• Protein at every meal. Eggs, chicken, fish, yoghurt, beans or tofu. Protein is the most filling nutrient and protects muscle while you lose weight.
• Volume from vegetables. A plate that is half vegetables lets you eat a large meal for very few calories. Salad, soup and stir-fried vegetables are your best friends.
• Fibre for staying power. Oats, whole grains, beans and fruit slow digestion and keep hunger away for hours.
• Watch liquid calories. Juice, sugary coffee and alcohol add hundreds of calories without filling you at all. Water and unsweetened tea cost nothing.
• Keep some foods you love. A plan that bans everything you enjoy lasts about ten days. Budget a small daily treat inside your target instead.
• Plan the week, not the day. One big meal does not ruin a diet — a week of them does. Think in weekly totals, like the calculator shows.

How Fast Should You Expect to Lose Weight?

Healthy weight loss is 0.5 to 1% of body weight a week. For a 90 kg person that is 0.45 to 0.9 kg a week; for a 60 kg person it is 0.3 to 0.6 kg. The first week is often faster because you lose water as well as fat, especially if you cut carbohydrates or salt. After that, expect the steady 0.5 kg a week the maths predicts — and expect plateaus. Weight loss is never a straight line: water retention, hormones and glycogen can hide a week of fat loss on the scale, then release it all at once.

When Your Weight Stops Moving

Every dieter hits a plateau, usually after 6 to 12 weeks. It happens because a lighter body burns fewer calories: the target that worked at 90 kg is too generous at 82 kg. When your weight has not moved for two full weeks, recalculate your target with your new weight. A 90 kg man who drops to 82 kg at the same height and age loses about 80 calories a day of BMR, and his maintenance falls by roughly 125 calories. That is often the whole plateau. Other fixes: check that you are still tracking honestly, add 2,000 steps a day, or raise protein. Do not slash another 500 calories in frustration — small adjustments beat dramatic ones.

Mistakes That Stall Weight Loss

• Under-recording food. Studies show people under-report intake by 20 to 50 percent. Weigh food for two weeks to calibrate your eye.
• Forgetting cooking oil and sauces. A tablespoon of oil is 120 calories, and most people pour two without noticing.
• Weekend blowouts. Five days at a 500 deficit is 2,500 calories saved; one 2,500-calorie Saturday erases the week.
• Choosing too big a deficit. A 1,000-calorie cut sounds faster, but hunger and fatigue usually end it within three weeks.
• Judging by one weigh-in. Weight swings 1 to 2 kg day to day with water. Weigh twice a week and compare weekly averages.
• Skipping strength training. Without it, up to a quarter of the weight you lose can be muscle, which lowers your BMR and makes keeping the weight off harder.

Using the Calculator for Your Plan

1. Enter your details and choose your honest activity level.
2. Select the “Lose weight” goal, which applies a 500-calorie deficit.
3. Note your daily target, your weekly total and your macro grams.
4. Plan three days of meals that hit the target, then repeat them.
5. Weigh yourself twice a week and compare weekly averages.
6. Recalculate your target every 5 kg lost, or every month.

Related tools: find your resting burn with the BMR calculator, see your full daily burn with the TDEE calculator, and check your weight category with the BMI calculator. The National Heart, Lung, and Blood Institute has guidance on safe, lasting weight loss.

Key Takeaways

Keep the reference figures below handy while you plan.

What to remember

• Your maintenance calories are your BMR times your activity factor — everything else is built on that number.
• A 500-calorie daily deficit loses about 0.5 kg a week; a 250 deficit loses about 0.25 kg.
• Never eat below 1,200 calories a day (women) or 1,500 (men) without medical supervision.
• Protein should be 1.6 to 2.0 g per kg of body weight a day when you train.
• Recalculate your target every 5 kg of weight lost, because a lighter body burns fewer calories.

Your checklist

1. Enter your sex, age, weight and height in the calculator above.
2. Choose the activity level that honestly matches your week.
3. Pick your goal and note your daily target and your macro grams.
4. Plan three days of meals that hit the target, then repeat them.
5. Weigh yourself twice a week and compare the weekly averages.

Mistakes to avoid

• Choosing too high an activity level — three gym sessions a week is moderately active, not very active.
• Counting exercise twice by adding watch calories on top of the activity multiplier.
• Forgetting drinks, sauces and cooking oil, which can add hundreds of calories.
• Judging progress by one weigh-in instead of the four-week trend.
• Never recalculating after losing weight, so the old target quietly becomes too high.

Frequently Asked Questions

How many calories should I eat to lose 0.5 kg a week?

Eat 500 calories a day below your maintenance level. If your maintenance is 2,556 calories, your target is 2,056 a day. That deficit adds up to about 3,500 calories a week, which is roughly 0.5 kg of body fat.

Is 1,200 calories a day safe for weight loss?

For most women, 1,200 is the lowest intake that can still cover basic nutrition, and only for short periods. For men the floor is 1,500. Below those levels you risk muscle loss, fatigue and nutrient deficiency. The calculator raises any target below the floor automatically.

Why am I not losing weight at a calorie deficit?

The most common reasons are under-recording food, weekend overeating that cancels the weekday deficit, or a target based on an activity level that is too high. Weigh food for two weeks, track weekends honestly, and recalculate with your current weight.

Should I use the mild or the standard weight-loss option?

Start with the standard 500-calorie deficit. If you are already fairly lean, feel very hungry, or have struggled with diets before, the mild 250-calorie deficit loses weight more slowly but is much easier to sustain for months.

Does exercise help if I already eat fewer calories?

Yes. Exercise burns extra calories, preserves muscle while you diet, and improves health in ways diet alone cannot. A 30-minute daily walk adds about 150 calories of burn and makes a 500 deficit feel like 350 in effort terms.

How often should I recalculate my calorie target?

Every 5 kg of weight lost, or at least once a month. A lighter body burns fewer calories, so a target that worked at your starting weight gradually becomes too high as you lose.

Disclaimer: This calculator provides estimates for general information only and is not medical or dietary advice. Weight loss can be unsafe for some people, including anyone pregnant, under 18, or with a history of eating disorders. Consult a doctor or registered dietitian before starting a weight-loss plan.