Ideal Weight Calculator (for Height & Age)

Clinical review: Tatiana Zanin
Registered Dietitian
December 2022

A person's ideal weight is often based on their height. Trying to stay within your ideal weight is important to avoid some serious health problems, such as obesity, hypertension, diabetes, or even malnutrition (when the person's weight is too low). To determine your ideal weight, you need to calculate your BMI (Body Mass Index), which your age, weight, and height takes into consideration. 

It's important to mention that BMI is just a reference, as it does not take your fat muscle, or water composition into account. If you a high muscle mass, for example, or suffer from fluid retention, calculating your ideal weight using your BMI may not be appropriate or accurate. In this case, a formal nutritional assessment by a health care professional is most recommended.

Ideal weight calculator

To calculate your ideal weight, enter your details below:


This calculator provides a rough idea of how much you should weigh according to your height, however, there are other important factors that should be taken into consideration, such as fat, muscle, and water composition.

If you have any concerns about your weight, you are advised to see a registered dietitian for a formal assessment. He or she will take many factors into consideration such as your lifestyle, your health history, your current activity status and your fat, muscle, and water composition.

Weight chart for children 

Following is a weight chart for girls up to the age of five years old:

1 month7 - 11 lb6 months14 - 18 lb18 months20 - 26 lb
2 months10 - 13 lb8 months15 - 20 lb2 years22 - 29 lb
3 months11- 15 lb9 months16 - 21 lb3 years24 - 35 lb
4 months12 - 16 lb10 months16 - 21 lb4 years31 - 41 lb
5 months13 - 17 lb11 months17 - 22 lb5 years34 - 47 lb
6 months14 - 18 lb12 months17 - 22 lb------------

The following chart is for boys up to five years old:

1 month7 - 11 lb7 months16 - 20 lb18 months22 - 27 lb
2 months11 - 14 lb8 months17 - 21 lb2 years24 - 30 lb
3 months12 - 16 lb9 months18 - 22 lb3 years28 - 36 lb
4 months14 - 17 lb10 months18 - 22 lb4 years32 - 41 lb
5 months15 - 19 lb11 months19 - 23 lb5 years35 - 47 lb
6 months15 - 19 lb12 months19 - 24 lb------------

With infants, ideal weight is related to the nutritional status and intake rather than height, and therefore weight is guided by age in months. The ratio between weight and height is only used in children that are two years old or older.

How to achieve your ideal weight 

If you are not at your ideal weight, you are advised to visit a registered dietitian to start a diet adapted to your goals. You should also visit a personal trainer to create a customized exercise plan.

Achieving your ideal weight will depend on whether you are trying to lose or gain weight.

1. If you are above your ideal weight 

If you are overweight and want to get down to your ideal weight, you should increase your intake of healthy food that is rich in fiber and low in calories. Examples include eggplant, ginger, salmon, and flaxseed. These foods help to accelerate metabolism and reduce anxiety, encouraging weight loss. See a list of foods rich in fiber.

To achieve your goal faster, you should engage in regular exercise so that you can increase energy expenditure and metabolism. A dietitian can indicate some teas and natural supplements, if necessary, to encourage weight loss and decrease anxiety. Learn some nutritional tips and exercise plan to lose weight in 1 week.

In cases of severe obesity, the doctor may prescribe medications that help with weight-loss, to be taken in conjunction with a suitable diet and a physical activity plan. Another option is bariatric surgery, which is indicated for those who struggle with obesity and are not able to lose weight through traditional methods.

In addition to knowing your ideal weight, it's also important to know your waist-hip ratio, as this can predict your risk for heart diseases, diabetes and stroke. 

2. If you are below your ideal weight

If your BMI is low and you are looking to gain weight, you should consult a dietitian for formal assessment and to get you started on a nutrition plan adapted to your individual needs.

Firstly, your increase in weight should be healthy through muscle hypertrophy and not through fat accumulation in the body. Therefore, having fast food such as pizza, fried food, hot dogs, and hamburgers is not the best option if you need to gain weight in a healthy way, as this type of fat can get stored in the arteries, increasing the risk of heart disease.

To increase muscle mass, it's important to increase your intake of protein with foods like eggs, cheese, dairy products, chicken, and salmon. You should also eat every three hours to increase calorie intake. See a list of high-protein foods.

In some cases, low weight can be due to a lack of appetite related to physical or emotional distress and the doctor may order tests to identify what the cause could be. 

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Edited by Tua Saude editing team in December 2022. Clinical review completed by Tatiana Zanin - Registered Dietitian in December 2022.


  • MAHAN, L. Kathleen et al. Krause: Alimentos, Nutrição e Dietoterapia. 13.ed. São Paulo: Elsevier Editora, 2013. 166.
  • ORGANIZACIÓN MUNDIAL DE LA SALUD (OMS). Patrones de crecimiento infantil. Available on: <>. Access in 17 May 2019
Clinical review:
Tatiana Zanin
Registered Dietitian
Graduated in Clinical Nutrition in 2001 and has a Master’s in Clinical Nutrition. Licensed to practice under the CRN-3 in Brazil and the ON in Portugal