What Should I Weigh?

About What Should I Weigh?

The What Should I Weigh? calculator helps you find a healthy weight range based on your height using Body Mass Index (BMI) guidelines from the World Health Organization (WHO) and the CDC. Enter your height to see your target weight range, a visual BMI spectrum, complete weight zone breakdown, and key milestones — for adults aged 20 and older.

What Should I Weigh for My Height?

Your healthy weight depends primarily on your height. Health organizations worldwide use BMI as a screening tool to classify weight status. A BMI between 18.5 and 24.9 is considered a normal (healthy) weight for most adults. By converting these BMI boundaries into actual weight for your height, we get your recommended weight range.

Here is a quick reference table for common heights:

Understanding BMI Categories

The World Health Organization defines these BMI categories for adults:

How Is My Healthy Weight Calculated?

This calculator uses the standard BMI formula to convert BMI boundaries into weight:

1. Convert height to meters: Height (m) = Height (inches) × 0.0254
2. Apply the BMI formula: Weight (kg) = BMI × Height (m)²
3. Calculate the healthy range: Using BMI 18.5 (minimum) and BMI 24.9 (maximum)
4. Find the ideal midpoint: BMI 21.7, which is at the center of the healthy range

In imperial units, the formula is: Weight (lbs) = BMI × Height (in)² ÷ 703

Age and Weight: What Changes?

The standard BMI range of 18.5–24.9 was developed for adults aged 20–65. However, research increasingly suggests adjustments for different life stages:

Adults (20–65)

The standard BMI range applies. Focus on maintaining a weight within 18.5–24.9 BMI through balanced nutrition and regular physical activity.

Seniors (65+)

Multiple studies suggest that older adults may benefit from a slightly higher BMI range of 23–30. A moderate amount of body weight provides protective reserves that help during illness, surgery, or recovery. Being underweight in old age is associated with greater health risks than being moderately overweight.

Limitations of BMI

While BMI is widely used and easy to calculate, it has important limitations:

• Muscle vs. fat: BMI cannot distinguish between lean muscle mass and body fat. Athletes may have a "overweight" BMI while having very low body fat.
• Body fat distribution: BMI does not indicate where fat is stored. Visceral fat (around organs) is more dangerous than subcutaneous fat (under the skin), but BMI cannot detect this difference.
• Ethnicity: Health risks associated with BMI vary across ethnic groups. For example, Asian populations may have higher health risks at lower BMI values.
• Age and sex: Women naturally have more body fat than men, and body composition changes with age. BMI does not account for these differences.
• Individual variation: Two people with identical BMIs can have very different levels of health. BMI is a population-level screening tool, not an individual diagnostic measure.

What Should I Weigh vs. How Much Should I Weigh

This website offers two related but different tools:

• What Should I Weigh? (this tool) — Focuses on BMI-based weight zones. Shows your healthy range plus a complete breakdown of all BMI categories converted to actual weight for your height.
• How Much Should I Weigh? — Uses 5 scientific formulas (Devine, Robinson, Miller, Hamwi, Peterson) to calculate specific ideal weight numbers, with gender and body frame adjustments.

For the most complete picture, try both tools and compare the results.

Tips for Reaching a Healthy Weight

• Set realistic goals: Aim for gradual changes of 1–2 pounds per week rather than rapid weight loss.
• Focus on nutrition: Emphasize whole foods, vegetables, lean proteins, and complex carbohydrates.
• Stay active: The CDC recommends at least 150 minutes of moderate aerobic activity per week.
• Monitor progress: Use a combination of metrics — weight, waist circumference, and how your clothes fit — rather than relying on the scale alone.
• Consult professionals: A registered dietitian or healthcare provider can offer personalized guidance.

Frequently Asked Questions

What should I weigh for my height?

Your healthy weight depends on your height and is determined using the Body Mass Index (BMI). A healthy BMI range is 18.5 to 24.9. For example, a person who is 5'4" (163 cm) should weigh between approximately 108 and 145 pounds (49–66 kg). A person who is 5'10" (178 cm) should weigh between approximately 129 and 174 pounds (58–79 kg).

How is healthy weight calculated?

Healthy weight is calculated using the BMI formula: BMI = weight (kg) ÷ height (m)². By rearranging this formula, you can find the weight range that corresponds to a healthy BMI of 18.5 to 24.9. The formula in imperial units is: BMI = 703 × weight (lbs) ÷ height (inches)².

What is a healthy BMI?

A healthy BMI for adults is between 18.5 and 24.9, according to the World Health Organization (WHO) and the CDC. Below 18.5 is considered underweight, 25.0–29.9 is overweight, and 30.0 or above is classified as obese. The ideal midpoint BMI is approximately 21.7.

Does age affect what I should weigh?

Yes, research suggests that older adults (65+) may benefit from a slightly higher BMI range of 23–30, as moderate weight provides protective reserves during illness and recovery. The standard BMI range of 18.5–24.9 was developed primarily for adults aged 20–65. Always consult a healthcare provider for age-appropriate guidance.

Is BMI accurate for everyone?

BMI is a useful screening tool but has limitations. It does not distinguish between muscle mass and fat mass, so athletes or highly muscular individuals may have a high BMI while being healthy. It also does not account for body fat distribution, bone density, ethnicity, or sex differences. BMI should be used as one of several indicators of health, not the sole measure.

What is the difference between "What Should I Weigh" and "How Much Should I Weigh"?

Both tools help determine a healthy weight. "What Should I Weigh" focuses on BMI-based weight ranges, giving you a complete zone breakdown from underweight to obese for your height. "How Much Should I Weigh" uses five scientific formulas (Devine, Robinson, Miller, Hamwi, Peterson) to calculate specific ideal weight numbers with gender and frame size adjustments.

Additional Resources

• Body Mass Index - Wikipedia
• Classification of Obesity - Wikipedia