How we calculate your targets

Your daily calorie target

We estimate the calories you burn in a day (your maintenance calories), then add or subtract a set amount for your goal. It takes three steps.

1. Resting burn (BMR)

With your age, sex, height and weight we use the Mifflin-St Jeor equation:

• Men: 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5
• Everyone else: 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161

If you give us an estimated body-fat percentage we switch to the Katch-McArdle equation, which uses lean mass instead:

• Lean mass (kg) = weight (kg) × (1 − body fat % ÷ 100)
• BMR = 370 + 21.6 × lean mass (kg)

Sources: Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. “A new predictive equation for resting energy expenditure in healthy individuals.” Am J Clin Nutr. 1990;51(2):241-247. PubMed record. Katch-McArdle: McArdle WD, Katch FI, Katch VL. Exercise Physiology: Nutrition, Energy, and Human Performance. Wolters Kluwer.

2. Activity

We combine how active your day is with how often you exercise to pick an activity level, then multiply your BMR by that level’s factor. These are the standard activity multipliers used by most calorie calculators; we have not tied them to a single published study.

• Mostly sitting Desk job, no planned workouts × 1.2
• Lightly active Desk job + lifting 1–3 times a week, or on your feet with no workouts × 1.375
• Moderately active Desk job + 4–5 workouts a week, or on your feet + 1–3 × 1.55
• Active Desk job + training 6 or more days, or on your feet + 4–5 workouts × 1.725
• Very active On your feet + 6 or more workouts, or heavy labour with no workouts × 1.9
• Extra active Heavy labour + 1–3 workouts a week × 1.9
• Athlete Heavy labour + 4 or more workouts a week × 2

The result is your maintenance calories, rounded to the nearest whole number. If we are missing your age, sex, height or weight we show a placeholder of 2,000 kcal until you add them.

3. Your goal

We treat 7,700 kcal as one kilogram of body fat. The pace you pick sets how many kilograms per week you aim to change, and that becomes a daily deficit (to lose) or surplus (to gain):

• Conservative · 0.25 kg per week 275 kcal a day
• Moderate · 0.50 kg per week 550 kcal a day
• Aggressive · 0.75 kg per week 825 kcal a day

We plan a loss of at most 1% of your weight per week, and we do not accept a goal date that needs more than 1.5% per week.

Daily target = maintenance − deficit to lose, maintenance + surplus to gain. If your goal weight is within 0.5 kg of your current weight, or your goal is to maintain, there is no adjustment and the target equals your maintenance calories. If you choose a goal date instead of a pace, the weekly change is the weight you want to move divided by the weeks until that date, converted the same way.

To protect you from eating too little, the target never drops below 1,500 kcal for men or 1,200 kcal for everyone else. These floors follow common dietary guidance; they are a convention, not a medical threshold.

Protein, fat and carbs

This split is CaloGoal’s own default, not taken from a published guideline. With the standard balanced plan:

• Protein: 1.8 g for every kg of lean mass (or of body weight if you have not given a body-fat percentage).
• Fat: 1.0 g for every kg of body weight.
• Carbs: whatever calories remain, at 4 kcal per gram of protein and carbs and 9 kcal per gram of fat.

Protein is set per kg of a reference weight, fat stays between 20% and 35% of your calories, and carbs fill the rest.

The other diet styles change the numbers: high protein uses 2.2 g protein per kg lean mass and 1.0 g fat per kg body weight; low carb fixes carbs at 100 g with 2.0 g protein per kg lean mass; keto fixes carbs at 30 g with 1.8 g protein per kg lean mass. Fat and carbs never go below zero.

Goal date and weight projection

At sign-up the projection is a straight line. We divide the weight you want to lose or gain by the weekly rate of your pace (0.25, 0.50 or 0.75 kg) and round up to whole weeks.

Once you log weight we smooth day-to-day swings with an exponential moving average (each new weigh-in counts 10%, the earlier trend 90%). The change in that trend over the last 7 days gives your weekly rate, and the date is the remaining weight divided by that rate. If you are moving the wrong way, we show the date you would reach if you started now at 0.5 kg a week (losing) or 0.35 kg a week (gaining). Dates more than two years away are not shown. If you set a goal date, you are “on track” when your weekly rate is within 20% of the rate that date needs.

Your real metabolism. After at least 7 days of food logs, 4 weigh-ins and a 7-day span, we compare what you ate with how your trend weight moved (using the same 7,700 kcal per kg) to estimate the calories you actually burn. We only show it when you logged food on at least half the days in that span, and it is labelled a draft until you have 14 days of food logs, 7 weigh-ins and a 14-day span. We only suggest changing your target; we never change it without your say-so.

We compare what you log with how your weight trend moves. A week counts only when at least 4 of its 7 days are logged, and one update moves the estimate by at most 150 kcal.

A projection is a forecast, not a promise. Real weight change is uneven and depends on things we cannot see.

Food estimates

When you log a meal with a photo or text, an AI model (Google Gemini) works out what the foods are and roughly how much you had. We then try to match each food against our own list of checked common foods and, for packaged products, against Open Food Facts and the USDA FoodData Central database. When nothing matches, the number is the AI’s own estimate and is marked as an estimate.

Portion sizes from a photo are the hardest part and can be off by a lot. Check each result and correct it before you save.

Product data from Open Food Facts is made available under the Open Database License (ODbL) 1.0; individual product entries are under the Database Contents License (DbCL) 1.0.

Sugar

Shown without a warning colour. The WHO limit is for free sugars (added sugar, honey, juice), and we cannot tell those apart from the natural sugar in fruit and milk.

Source: WHO guideline on sugars intake (2015)

Fibre

Your line is 14 g for every 1,000 kcal of your calorie target. The number turns green once you reach it.

Source: US Institute of Medicine, Adequate Intake for fibre

Sodium

Turns red above 2,300 mg in a day. The WHO suggests staying under 2,000 mg.

Source: US National Academies (2,300 mg); WHO (2,000 mg)

Water goal

Unless you set your own goal: 1.6 litres a day from drinks for women and 2.0 litres for men. About a fifth of the water you need comes from food.

Source: EFSA reference values for water (2010)

Health Grade

Health Grade is calculated from each meal's nutrients per 100 g using the published Nutri-Score 2023 algorithm. It is our own rating, not the official Nutri-Score label.

Calculated from this meal's nutrients per 100 g with the published Nutri-Score 2023 maths: energy, sugars, saturated fat and salt count against it; protein and fibre count for it. Five steps, from most to least favourable.

• Not enough data
• Not graded (drinks)

Source: Santé publique France, Nutri-Score 2023 algorithm