BMI for 90 kg and 170 cm
Instant answer: A person who weighs 90 kg (198 lbs) and is 170 cm (5'7") tall has a BMI of 31.1, classified as obese class i.
At 170 cm, the BMI-based healthy weight range spans 53.5 kg to 72 kg, with the midpoint considered the most statistically protective.
What does a BMI of 31.1 mean?
Modern guidelines (NICE, WHO) now treat obesity as a chronic disease with multiple effective treatment pathways, including structured lifestyle programmes, medication, and surgery.
BMI is a screening tool, not a diagnosis. Two people at 90 kg and 170 cm can have very different body compositions and very different health profiles. Use BMI alongside waist circumference, fitness level, and routine bloodwork.
Healthy weight range for 170 cm
The BMI-based healthy weight range for 170 cm tall adults is 53.5–72 kg (118–159 lbs).
| Weight | In lbs | BMI | Category |
|---|---|---|---|
| 75 kg | 165 lbs | 26.0 | Overweight |
| 80 kg | 176 lbs | 27.7 | Overweight |
| 85 kg | 187 lbs | 29.4 | Overweight |
| 90 kg (this page) | 198 lbs | 31.1 | Obese Class I |
| 95 kg | 209 lbs | 32.9 | Obese Class I |
| 100 kg | 220 lbs | 34.6 | Obese Class I |
| 105 kg | 231 lbs | 36.3 | Obese Class II |
Practical next steps
- Engage a multidisciplinary approach: dietitian, GP, and where appropriate behavioural support.
- Start with low-impact movement (walking, swimming, cycling) to protect joints.
- Address sleep apnoea risk if snoring or daytime fatigue is present.
- Track non-scale wins — energy, mobility, blood pressure — alongside weight.
Frequently asked questions
What is the BMI for 90 kg and 170 cm?
Using the formula BMI = weight (kg) ÷ height (m)², a person who weighs 90 kg and is 170 cm tall has a BMI of 31.1. This places them in the obese class i category as defined by the World Health Organization.
Is 90 kg a healthy weight at 170 cm?
The healthy weight range for 170 cm is 53.5–72 kg, corresponding to a BMI of 18.5–24.9. 90 kg gives a BMI of 31.1, which is obese class i.
How was this BMI calculated?
BMI = 90 ÷ (1.70 × 1.70) = 90 ÷ 2.8900 = 31.1.
What should I do if my BMI is 31.1?
Engage a multidisciplinary approach: dietitian, GP, and where appropriate behavioural support. Start with low-impact movement (walking, swimming, cycling) to protect joints.