Calorie Needs Estimate
y to Lose Up ToPounds of Pure Body Fat in the Next 30 days

The total calories (kcal) consumed each day by men varies from 1500-4000 for most males: the total for females varies from 900-2500. In extreme cases, calorie intake can vary wildly, from 0 for someone on a water fast, to over 8000 kcal for a logger who burns them all while working, without gaining an ounce, and as high as 12,000 kcal per day for weight-lifters and bodybuilders.

What Determines Energy Needs

Our calorie needs are typically determined by a number of factors, including:

- Our present weight
- Our height
- Our age
- Our gender
- Our exercise routine
- Our health
- Our body-fat-percentage
- Our environment
- How fast we want to lose weight

To obtain an accurate assessment of our calorie needs, all these factors need to be considered.

Rough Estimate of Calorie Needs to Lose Weight

Here is a very rough guide of how many calories you need per day, if you want to lose weight. It's a ballpark estimate only.

Teenagers need about 1500-1800 calories per day

Women (Non-Active)
Sedentary women typically need about 1100-1300 calories per day

Women (Active)
Active women typically need about 1400-1600 calories per day

Men (Non-Active)
Sedentary men typically need about 1600-1800 calories per day

Men (Active)
Active men typically need about 1800-2000 calories per day

Quick Estimate of Calorie Needs

Here is a very rough and ready guide to calculating your calorie needs. Just be careful to maintain your daily calorie intake above 1000 calories, minimum.


To Maintain Weight - Multiply your weight (in pounds) by 12
This is a rough estimate of daily calories needed to maintain weight.

To Lose Weight - Deduct 500 calories from this figure
This gives you a rough estimate of the daily calories needed for you to lose about 1 pound per week.


To Maintain Weight - Multiply your weight (in pounds) by 14
This is a rough estimate of daily calories needed to maintain weight.

To Lose Weight - Deduct 500 calories from this figure
This gives you a rough estimate of the daily calories you need to lose about 1 pound per week.

Calorie Needs for Women

How many calories you need depends on various factors, including height, total body weight, ratio of fat to muscle, age, gender, genes and physical exercise. (Plus illness, pregnancy etc.) But usually, a woman's calorie needs can be reasonably accurately assessed by focusing on two calorie components. Basal Metabolic Rate (BMR) and physical exercise.

Calorie Needs for Women and Basal Metabolic Rate

Basal Metabolic Rate is a short way of saying: "the amount of energy (calories) you need to keep your body functioning while at rest." A body needs a minimum number of calories to maintain the millions of chemical reactions which keep eyes, lungs, heart, liver, kidneys etc. in healthy working order. This is your Basal Metabolic Rate. Over half the calories needed by most women fuel these basic bodily functions.

Calorie Needs for Women and Exercise

The second major calorie-needs component is physical activity. The more exercise you take, the more calories you need.

Calorie Needs for Women - Weight Maintenance and Weight Gain

When you have determined your total daily calorie needs, this will be the number of calories required to maintain your weight. If you want to lose weight, (e.g. one pound per week), you should consume 3,500 calories less, per week. (Or, consume 2,000 fewer calories and burn an extra 1,500 calories by taking extra exercise.) This is because one pound of weight is equal to 3,500 calories. To gain one pound of weight, increase your calorie intake by 3,500 calories.

Harris-Benedict Formula to Determine Calorie Needs for Women

The determines calorie needs for women in two steps:

  • It calculates your Basal Metabolic Rate (BMR) calorie requirements, based on your height, weight, age and gender.

  • It increases your BMR calorie needs by taking into account the number of calories you burn by taking exercise. This gives you your total calorie requirement.

Drawback of Harris-Benedict Calorie Needs Formula

The only calorie variable which the Harris-Benedict formula does not take into consideration is lean body mass. Therefore, this equation will be accurate for most women except the extremely muscular (these women need more calories) and the extremely fat (these women need fewer calories).

The Harris Benedict Calorie Needs Formula for Women

  • First, calculate your BMR according to this formula:
    655 + (9.6 x weight in kilos) + (1.8 x height in centimeters) - (4.7 x age in yrs)

  • To Calculate your total calorie needs, multiply your BMR by the appropriate activity multiplier:

Activity Multiplier

  • If you are sedentary (little or no exercise, desk job) multiply BMR by 1.2
  • If you are lightly active (light exercise/sports 1-3 days per week) multiply your BMR by 1.375

  • If you are mod. active (moderate exercise/sports 3-5 days per week) multiply your BMR by 1.55

  • If you take heavy exercise (hard exercise/sports 6-7 days per week) multiply your BMR by 1.725