Calorie Calculator

Maintenance calories are your BMR times an activity factor: a moderately active 30-year-old man who is 175 cm and 70 kg burns about 2,556 kcal a day (1,649 × 1.55), so eating 2,006 kcal a day loses about 0.5 kg a week. Targets cover losing or gaining 0.25 to 1 kg (0.5 to 2 lb) a week.

By the Calculators With Steps team · Updated November 10, 2026 · How we check our math

Maintenance calories

2,556 kcal/day

to keep your current weight · moderately active (BMR × 1.55)

BMR (Mifflin-St Jeor): 1,649 kcalcalories burned at complete rest
To lose 0.5 kg a week: 2,006 kcal/day550 kcal a day below maintenance
To gain 0.5 kg a week: 3,106 kcal/day550 kcal a day above maintenance
Suggested minimum intake: 1,500 kcal/daycommon floor for men without medical supervision

Step-by-step working

BMR = 10 × 70 kg + 6.25 × 175 cm − 5 × 30 + 5 = 1,648.75 kcal/day
Maintenance = BMR × 1.55 (moderately active) = 2,555.56 ≈ 2,556 kcal/day
0.5 kg a week × 7,700 kcal per kg ÷ 7 days = 550 kcal a day
To lose 0.5 kg a week: 2,556 − 550 = 2,006 kcal/day

Daily calories for each goal

Goal	Weight change	Calories per day	kcal vs maintenance	% of maintenance
Maintain weight	No change	2,556 kcal	0	100%
Mild weight loss	−0.25 kg a week	2,281 kcal	−275	89%
Weight loss	−0.5 kg a week	2,006 kcal	−550	78%
Extreme weight loss	−1 kg a week	1,456 kcal (below 1,500 minimum)	−1,100	57%
Mild weight gain	+0.25 kg a week	2,831 kcal	+275	111%
Weight gain	+0.5 kg a week	3,106 kcal	+550	122%

Extreme weight loss would take you below 1,500 kcal a day, the usual minimum for men without medical supervision. Choose a slower rate instead. Estimates use the Mifflin-St Jeor equation and the 7,700 kcal per kg (3,500 kcal per lb) rule of thumb, which overstates loss after the first few weeks as your body adapts. Weigh yourself for 2 to 3 weeks and adjust by 100 to 200 kcal if the trend doesn't match.

How to use the calorie calculator

Pick Metric (kg, cm) or US (lb, ft, in).
Enter your sex, age, height and weight.
Choose the activity level that matches a typical week. Count your job as well as planned exercise.

The result shows your maintenance calories (what you burn in a day), your basal metabolic rate and a table of daily calorie targets for losing or gaining weight at different speeds. Any target below the usual safe minimum is flagged.

How the calorie calculator works

First it estimates your basal metabolic rate (BMR), the energy you burn at complete rest, with the Mifflin-St Jeor equation:

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

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

Then it multiplies BMR by an activity factor to get your maintenance calories, also called total daily energy expenditure:

Activity level	Factor	What it means
Sedentary	1.2	Desk job, little or no exercise
Lightly active	1.375	Light exercise or sport 1–3 days a week
Moderately active	1.55	Moderate exercise 3–5 days a week
Very active	1.725	Hard exercise 6–7 days a week
Extra active	1.9	Very hard training or a physical job

Finally it adds or subtracts calories for your goal, using the rule of thumb that 1 kg of body weight holds about 7,700 kcal (3,500 kcal per lb).

Worked example

A 30-year-old man, 175 cm tall and 70 kg, who exercises 3 to 5 days a week:

BMR = 10 × 70 + 6.25 × 175 − 5 × 30 + 5 = 1,648.75 kcal
Maintenance = 1,648.75 × 1.55 = 2,556 kcal a day

Goal	Change per week	Calories per day
Maintain weight	None	2,556
Mild weight loss	−0.25 kg	2,281
Weight loss	−0.5 kg	2,006
Extreme weight loss	−1 kg	1,456 (below the 1,500 minimum)
Mild weight gain	+0.25 kg	2,831
Weight gain	+0.5 kg	3,106

In US units the same man at 5 ft 9 in and 155 lb gets 2,563 kcal for maintenance and 2,063 kcal to lose 1 lb a week. The small difference comes from rounding the height and weight.

How many calories to lose weight

A calorie deficit makes your body draw on stored energy. The 7,700 kcal per kg rule says a 550 kcal daily deficit should take off about 0.5 kg a week, and a 500 kcal deficit about 1 lb a week. It is a useful first estimate, but it has limits:

The first week or two often shows a faster drop because you lose stored carbohydrate and water.
As you get lighter you burn less. In the example above, losing 5 kg lowers maintenance from 2,556 to 2,478 kcal, so the same intake gives a smaller deficit.
Your body adapts by moving a little less and becoming more efficient.

Research using a dynamic model (Hall et al., 2011) found weight responds slowly: a lasting change of about 100 kJ (24 kcal) a day eventually shifts weight by about 1 kg, with half of that change taking about a year. The NIH Body Weight Planner uses this model if you want a week-by-week forecast.

Minimum calories and safe rates of loss

A loss of 0.5 to 1 kg (1 to 2 lb) a week is the usual guide for adults with weight to lose. Most guidelines also advise against eating below about 1,200 kcal a day for women or 1,500 kcal for men without medical supervision.

That floor matters most for smaller, less active people. A 35-year-old woman who is 165 cm, 65 kg and lightly active has maintenance of 1,850 kcal. Losing 0.5 kg a week means 1,300 kcal a day, which is workable, but losing 1 kg a week would mean just 750 kcal. For her, a slower target plus more daily movement is the better route.

Calories to gain weight

To gain weight, eat 275 to 550 kcal a day above maintenance. Combine the surplus with strength training and enough protein, and more of the gain will be muscle rather than fat. The protein calculator gives a daily protein target, and the macro calculator splits your calories into protein, carbs and fat.

Tips for using your number

Weigh yourself at the same time each day and compare weekly averages, not single readings.
If your weight hasn’t moved after 2 to 3 weeks, lower your intake by 100 to 200 kcal, or raise it if you are losing faster than planned.
Recalculate after every 4 to 5 kg of change.
If you only want your resting burn, use the BMR calculator. To compare every activity level side by side, try the TDEE calculator.

Calorie Calculator: frequently asked questions

How many calories should I eat a day?

It depends on your size, age, sex and activity. A 30-year-old man who is 175 cm tall, weighs 70 kg and is moderately active burns about 2,556 kcal a day. A 35-year-old woman who is 165 cm, 65 kg and lightly active burns about 1,850 kcal. Eating that amount keeps your weight steady.

How do I calculate my calorie deficit for weight loss?

Find your maintenance calories (BMR × activity factor), then subtract the deficit. Losing 0.5 kg a week takes about 550 kcal a day (0.5 × 7,700 ÷ 7), and losing 1 lb a week takes about 500 kcal a day (3,500 ÷ 7). With maintenance of 2,556 kcal, that means eating about 2,006 kcal.

What is a calorie deficit?

A calorie deficit means eating fewer calories than your body burns, so it draws on stored energy, mostly fat. A moderate deficit of 250 to 550 kcal a day is easier to keep up and protects muscle better than a crash diet.

How many calories should I eat to lose 1 kg a week?

Losing 1 kg a week needs a deficit of about 1,100 kcal a day. That is too aggressive for most people. For the 35-year-old woman in our example it would mean eating only 750 kcal a day, far below the usual 1,200 kcal minimum, so a 0.25 to 0.5 kg weekly target is safer.

How many calories should I eat to gain weight?

Add about 275 to 550 kcal a day to your maintenance calories to gain 0.25 to 0.5 kg a week. For a man with maintenance of 2,556 kcal that is 2,831 to 3,106 kcal. Pair the surplus with strength training and enough protein so more of the gain is muscle.

Is 1,200 calories a day too low?

For many women 1,200 kcal is the lowest intake usually advised without medical supervision, and for men the figure is about 1,500 kcal. Going lower makes it hard to get enough protein, vitamins and minerals and speeds up muscle loss.

How accurate is this calorie calculator?

A 2005 systematic review found Mifflin-St Jeor predicted resting metabolism within 10% of measured values in more people than any other common equation. The bigger source of error is the activity level, so treat the result as a starting point and adjust it after 2 to 3 weeks of weighing yourself.

What is calorie cycling?

Calorie cycling means eating more on some days (often training days) and less on others while keeping the same weekly total. Weight change depends on the weekly average, so cycling is a matter of preference rather than a faster way to lose fat.

Disclaimer: This tool gives general estimates for information only and is not medical advice. Individual needs vary with health conditions, medications, pregnancy and other factors, so talk to a doctor or registered dietitian before you change your diet, exercise or treatment.

How we checked this page: every figure in the examples and FAQs above is produced by this calculator and verified by automated tests against known answers, and the rules and rates come from the sources below. Last updated November 10, 2026. Spotted a problem? Tell us.

Sources and further reading