Each person requires a different number of calories per day. The number of calories varies depending on the person's gender, size and level of activity. The number of calories should be reduced if a person is trying to lose weight or increased if trying to gain weight. With a few calculations, you can determine how many calories you need in a day.

### Things You'll Need

- Scale

- Calculator

Weigh yourself without your clothes when you wake up in the morning. This is the most accurate way to assess your current weight.

Multiply your body weight by 10 if you are an adult. For example, if you weigh 150 pounds, the figure would be 1500.

Add your body weight to the total if you are a woman. For example, a 130 pound woman would add 1500 + 130. The result is 1630 calories per day. This formula works for average sized women weighing between 100 and 160 pounds.

Add twice your body weight to the total if you are a man. For example, a 170 pound man would add 1500 + 340. The result is 1840 calories per day. This formula works for average sized men weighing between 130 and 220 pounds.

Calculate your daily calorie intake differently if you are trying to lose a little weight or do not get much exercise. Instead of using the other formula, multiply body weight by 10. For example, a 150 pound person should consume 150 x 10 = 1500 calories per day. This formula works for both men and women.

Consult a doctor if you are trying to lose 20 pounds or more. A doctor could recommend a diet with as few as 1200 calories per day regardless of current body weight. However, only do this under the advice and supervision of a doctor.

Increase your daily calorie intake if you are a very active person, a fit athlete or trying to gain wait. People who exercise at least one hour a day at least five days per week fit into this category. A simple way to calculate an increased calorie diet is to multiply body weight by 20. For example, an active 150 pound adult could consume 150 x 20 = 3000 calories per day. This formula works for both men and women. Individuals need to watch their weight to determine whether increasing calories to this level causes weight gain.

## Tips & Warnings

- Always consult a doctor before drastically reducing or increasing your calorie intake.