English
How to use the calorie calculator
This calorie calculator estimates how many calories you burn in a day and turns that into a target for losing, keeping or gaining weight. It takes about half a minute.
- Choose metric or imperial, then enter your sex, age, weight and height.
- Pick the activity level that matches a normal week, not your best week. If you are stuck between two, take the lower one.
- Choose a goal. For weight loss or gain, set the weekly change (0.5 kg or 1 lb is a sensible start) and, if you like, a goal weight to see a rough timeline.
- Read your daily target, then check the macro split and the two tables underneath. Press Save as PDF to keep a copy.
The pace table is the part most people skip and shouldn't. It shows what each weekly pace costs you in calories, and flags the ones that fall below the minimums usually advised without supervision.
What are BMR and TDEE?
BMR (basal metabolic rate) is the energy your body uses at complete rest: breathing, circulation, keeping warm. TDEE (total daily energy expenditure) adds everything you do on top, which is why it is also called your maintenance calories. Eat at TDEE and your weight stays roughly flat.
Women: BMR = 10 × kg + 6.25 × cm − 5 × age − 161
TDEE = BMR × activity factor
This is the Mifflin-St Jeor equation, published in 1990 and the one most dietetic reviews recommend for healthy adults. Example: a 30-year-old woman, 165 cm, 68 kg. That is 680 + 1,031 − 150 − 161 = 1,400 kcal of BMR. With light activity (× 1.375) her maintenance is about 1,925 kcal.
Activity factors
| Level | Factor | Typical week | Example TDEE |
|---|---|---|---|
| Sedentary | 1.2 | Desk job, little exercise | 1,680 |
| Light | 1.375 | Exercise 1 to 3 days | 1,925 |
| Moderate | 1.55 | Exercise 3 to 5 days | 2,170 |
| Very active | 1.725 | Hard exercise 6 to 7 days | 2,415 |
| Extra active | 1.9 | Physical job plus training | 2,660 |
The example column uses the 1,400 kcal BMR above. Notice the gap between the first and last row: nearly 1,000 kcal. Picking the wrong level is the biggest source of error in any calorie calculator, and almost everyone picks too high.
How many calories to lose weight?
A pound of body weight is commonly taken as about 3,500 kcal, and a kilogram as about 7,700 kcal. So a 500 kcal daily deficit is roughly 1 lb a week, and 550 kcal a day is about 0.5 kg. For the woman above:
| Pace | Calories per day |
|---|---|
| Maintain | 1,925 |
| Lose 0.25 kg a week | 1,650 |
| Lose 0.5 kg a week | 1,375 |
| Lose 0.75 kg a week | 1,100 |
The last row is below 1,200 kcal, which is why she shouldn't pick it. A slower pace is the better choice, and it is easier to stick to. Real weight loss also slows over time because a lighter body burns less, so recalculate every few kilos.
How are macros worked out?
Protein and carbohydrate provide 4 kcal per gram, fat provides 9. The calculator takes your daily target, applies the percentage split you choose and converts it to grams. On 1,375 kcal with the balanced 50/20/30 split you get about 172 g carbs, 69 g protein and 46 g fat. The higher-protein option raises protein to 30% of calories, which is a personal preference rather than a requirement. If you want a specific protein intake, a dietitian can set one for your situation.
Does it work for everyone?
No. The equations were built on healthy adults. They are not meant for pregnancy, breastfeeding, children and teenagers, people with eating disorders or medical conditions that change energy needs, or competitive athletes with very high training loads. Even for a healthy adult the result can be off by around 10%. Weigh yourself under the same conditions for two or three weeks, and if the scale hasn't moved, adjust by 100 to 200 kcal.
This page gives estimates only. Talk to your doctor or a registered dietitian before starting a calorie deficit, particularly if you take medication or have a health condition.
Frequently asked questions
How many calories should I eat a day?
It depends on your size, age and activity, so there is no single number. A 30-year-old woman who is 165 cm and 68 kg and exercises lightly burns about 1,925 kcal a day, which is her maintenance level. Eating below that loses weight, eating above it gains.
How do I calculate my BMR?
With the Mifflin-St Jeor equation: 10 × weight (kg) + 6.25 × height (cm) − 5 × age, then +5 for men or −161 for women. For a 30-year-old woman at 165 cm and 68 kg that gives 1,400 kcal, what her body uses at complete rest.
What is TDEE and which activity level should I choose?
TDEE is total daily energy expenditure: your BMR multiplied by an activity factor from 1.2 (sedentary) to 1.9 (extra active). If you hesitate between two levels, choose the lower one, because most people overestimate how active they are.
How many calories do I need to cut to lose 1 lb or 1 kg a week?
About 500 kcal a day for 1 lb a week and about 1,100 kcal a day for 1 kg a week, based on the usual rule of 3,500 kcal per lb (7,700 per kg) of body weight. It is an approximation, and weight loss usually slows as you get lighter.
What is a safe calorie deficit?
A common starting point is a deficit of 300 to 500 kcal a day, which is roughly 0.3 to 0.5 kg a week. Guidance such as the CDC's mentions about 1 to 2 lb (0.5 to 1 kg) a week as a steady pace. Do not go below 1,200 kcal (women) or 1,500 kcal (men) without medical supervision.
Is Mifflin-St Jeor or Harris-Benedict more accurate?
Mifflin-St Jeor, published in 1990, is the one most dietetic reviews prefer for healthy adults today. The Harris-Benedict equation dates from 1919 and tends to run a bit high. Both are estimates, usually within about 10% for most people.
How accurate is an online calorie calculator?
Treat the result as a starting point, not a measurement. Two people with the same numbers can differ by a couple of hundred kcal a day. Follow the plan for two to three weeks, track your weight, and adjust by 100 to 200 kcal if nothing moves.
How many calories are in protein, carbs and fat?
Protein and carbohydrate give 4 kcal per gram, fat gives 9 kcal per gram. So a 1,400 kcal day split 50% carbs, 20% protein and 30% fat is about 175 g carbs, 70 g protein and 47 g fat.