How do I calculate BMI using pounds and inches?

To calculate BMI in pounds and inches, use the formula BMI = (weight in pounds ÷ height in inches squared) × 703. Our BMI calculator does this automatically for you when you choose the imperial option for adults in the US, UK, Canada and other countries that use pounds and feet.

What is a healthy BMI range for adults in the US and UK?

For most adults in the US, UK, Canada, Australia and Europe, a healthy BMI range is 18.5 to 24.9. A BMI below 18.5 is considered underweight, 25.0 to 29.9 is overweight and 30 or higher falls into the obesity range.

What BMI is considered overweight or obese?

A BMI between 25.0 and 29.9 is classed as overweight, while 30.0 and above is classed as obese. Obesity is often separated into Class I (30.0–34.9), Class II (35.0–39.9) and Class III (40 or higher) for adults in Western countries.

Can I use this BMI calculator if I am very muscular or an athlete?

If you are very muscular, your BMI might look high even if your body fat is low, because BMI does not distinguish between muscle and fat. Use this BMI calculator as a rough guide only and combine it with other checks such as body fat percentage and waist measurement.

Is this BMI calculator suitable for children or teenagers?

No. This online BMI calculator is designed for adults only. Children and teenagers need age and sex specific BMI-for-age charts, which are provided by pediatric growth charts from health authorities and your doctor.

How can I lower my BMI safely?

The safest way to lower BMI is to combine a small, consistent calorie deficit with more daily movement and strength training. Using tools like a calorie calculator, BMR calculator and protein calculator can help you set realistic targets. Always speak to a healthcare professional before making big lifestyle changes.

How often should I check my BMI when losing weight?

For most adults it is enough to check BMI every one to four weeks. Checking every day is not necessary and normal fluid changes can make the number jump around. Focus on slow, steady trends instead of daily fluctuations.

Does BMI tell me everything about my health?

No. BMI is a quick screening tool, not a full health check. It does not show body fat distribution, muscle mass, blood pressure, cholesterol or blood sugar. Use BMI together with other measurements and medical advice from your doctor.

BMI Calculator 2025 – Body Mass Index for Adults (US/UK)

📊 Body Mass Index (BMI) Calculator for Adults

Weight (kg)

Height (cm)

0.0

BMI Range	Category	Health Risk	General Recommendation
< 16.0	Severe Underweight	Very High	Speak to a healthcare provider urgently about weight and nutrition.
16.0 – 18.4	Underweight	Moderate	Increase calories with nutrient-dense foods and get medical advice.
18.5 – 24.9	Normal Weight	Low	Maintain a balanced diet, regular movement and good sleep habits.
25.0 – 29.9	Overweight	Moderate	Start small changes to food choices and activity to lower risk.
30.0 – 34.9	Obese Class I	High	Discuss a structured weight-loss plan with a healthcare professional.
35.0 – 39.9	Obese Class II	Very High	Medical supervision and a tailored lifestyle program are recommended.
≥ 40.0	Obese Class III	Extremely High	Seek specialist support as soon as possible for safe weight management.

BMI Calculator 2025: Simple Guide for Adults in the US, UK & Worldwide

Body Mass Index (BMI) is a quick way to see how your weight compares to your height. It’s used by doctors and health organizations in the US, UK, Canada, Australia and Europe to group adults into categories like underweight, healthy weight, overweight and obese. BMI doesn’t tell the whole story about your health, but it is a fast, free starting point you can check from your couch.

How This BMI Calculator Works (kg/cm & lbs/ft)

You can use this page in either metric or imperial mode:

        Metric formula: BMI = weight (kg) ÷ height² (m²)

        Example: 70 kg ÷ (1.75 m)² ≈ 22.9

        Imperial formula: BMI = (weight (lbs) ÷ height² (in²)) × 703

        Example: (154 lbs ÷ (67 in)²) × 703 ≈ 24.1

Instead of doing the math by hand, simply choose Metric (kg, cm) or Imperial (lbs, ft/in), enter your numbers and hit Calculate BMI. The calculator instantly shows your BMI, category and a healthy weight range for your height. You can even download a TXT or CSV report for your doctor, coach or records.

BMI Ranges for Adults in Western Countries

Most national health services in Western countries use the same BMI ranges for adults:

Underweight: BMI < 18.5
Healthy weight: BMI 18.5 – 24.9
Overweight: BMI 25.0 – 29.9
Obesity (Class I–III): BMI ≥ 30

A BMI in the healthy range is usually linked with a lower risk of type 2 diabetes, high blood pressure and heart disease. If your BMI is above or below this range, it doesn’t mean you are “good” or “bad” – it simply means it’s worth looking a bit closer at your lifestyle and health habits.

What a Low or High BMI Can Mean

A very low BMI can be a sign of under-eating, nutrient deficiencies, long-term illness or other health issues. You might notice low energy, feeling cold all the time or getting sick easily.

A high BMI (overweight or obese) raises the chances of conditions such as type 2 diabetes, heart disease, joint problems and sleep apnea, especially if most of the extra weight is around your waist. Even a small change matters – losing or gaining just 5–10% of your body weight can improve blood pressure, blood sugar and cholesterol.

Quick BMI examples:

Healthy BMI: 170 cm & 65 kg → BMI ≈ 22.5 (Healthy weight)
Overweight BMI: 178 cm & 90 kg → BMI ≈ 28.4 (Overweight)
Obese BMI: 163 cm & 91 kg → BMI ≈ 34.3 (Obese Class I)

When BMI Is Not the Full Picture

BMI was designed for population-level trends, not to judge any single person. It does not separate muscle from body fat, so athletes and people who lift weights can have a “high” BMI with a low body fat percentage. It also doesn’t show where fat sits on your body, which matters for health risk.

To get a clearer picture you can combine this tool with our Body Fat Calculator and Calorie Calculator, then talk through the results with a doctor or dietitian. For general money planning around gym memberships or nutrition, you can also use our Budget Calculator and Loan Calculator.

How to Move Toward a Healthier BMI

If your BMI is above the healthy range, focus on realistic changes you can live with for months and years, not crash diets that last a week. Many adults in the US, UK and Europe have success by:

Tracking daily calories with a tool like our Calorie Calculator
Using the BMR Calculator to estimate daily energy needs
Eating more whole foods: vegetables, fruit, lean protein and high-fiber carbs
Walking more, taking the stairs and adding 2–3 strength workouts per week

If your BMI is below the healthy range, the goal is the opposite: gently increase calories with nutrient-dense foods and add resistance training to gain muscle. In both cases, it’s smart to involve a healthcare professional if you have existing conditions or take medication.

Important Reminder

This BMI calculator is for general information and education only. It is not a medical diagnosis tool and does not replace professional advice. Always speak with a qualified healthcare provider about your personal health, especially before starting any weight-loss or weight-gain plan.

BMI Calculator – Frequently Asked Questions for Adults

How do I use this BMI calculator correctly?

Choose metric if you know your weight in kilograms and height in centimeters, or imperial if you use pounds and feet. Enter your usual, stable weight and height, press Calculate BMI and read the BMI number and category. You can switch between units at any time.

What is a good BMI for adults in the US or UK?

For most adults in the US, UK, Canada, Australia and Europe, a BMI between 18.5 and 24.9 is considered a healthy range. The “best” number inside that range depends on your build, age, lifestyle and medical history, so your doctor can help you set a realistic personal target.

Is BMI reliable if I lift weights or play sports?

If you are very muscular, BMI can label you as overweight or obese even when your body fat is low. In that case, use this calculator as a rough guide only and combine it with body fat estimates, waist size and performance markers like strength, endurance and how you actually feel.

Can I use this BMI calculator for children or teenagers?

No. This page is built for adults aged 18 and over. Children and teenagers use special BMI-for-age growth charts that compare them with other people of the same age and sex. For kids, talk to a pediatrician or family doctor instead of relying on an adult BMI calculator.

How fast should I try to change my BMI?

Most guidelines for adults recommend slow, steady change: roughly 0.25–1.0 kg (0.5–2 lb) per week, depending on your starting point. Extreme diets that promise very rapid weight loss are harder to maintain and can be risky without medical supervision.

Will my BMI be different if I live in the US, UK or Europe?

The BMI formula and cut-offs are the same in most Western countries. However, some regions and ethnicities may have different risk levels at the same BMI. For example, people of South Asian origin can have higher health risks at lower BMI values, so local medical advice is important.

Which other calculators should I use with this one?

Many people use this BMI Calculator together with our BMR Calculator, Calorie Calculator, Body Fat Calculator and Percentage Calculator to plan realistic goals and track progress over time.

BMI Calculator 2025 – Check Your BMI in kg/cm or lbs/ft