BMI for 70 kg and 173 cm

What each BMI threshold weighs at 173 cm

The adult BMI cut-offs are the same for everyone. What changes with height is the body weight each cut-off corresponds to. At 173 cm those weights are:

Is the result different for men and women?

For adults, neither the BMI formula nor the standard BMI category thresholds change with sex, so this result is the same for a man and a woman of this height and weight. Body composition does differ on average between men and women, which is one reason BMI is a screening measure rather than a body-fat measurement. Sex-specific measures such as waist thresholds are a separate consideration and are shown further down this page.

How this page calculates the numbers

BMI = weight in kilograms ÷ height in metres squared. Here: 70 ÷ (1.73 × 1.73) = 70 ÷ 2.9929 = 23.4. The category comes from the unrounded value, so a result sitting a hundredth away from a cut-off is never rounded across it.

The weights shown for BMI 18.5, 25, 30, 35 and 40 are the same equation solved the other way round: weight = BMI × height². The thresholds themselves are unchanged — only their kilogram equivalent at 173 cm is calculated here.

Category definitions follow the World Health Organization adult classification, with waist guidance from NICE. BMI is a screening measure for adults from 18 years, not a diagnosis, and it says nothing about how much of a person's weight is muscle.

What the numbers mean for you

You have 4.8 kg (11 lbs) of headroom before crossing into overweight (BMI 25 = 74.8 kg (165 lbs)).

The arithmetic midpoint of the healthy band at this height is BMI 21.7 (64.9 kg (143 lbs)). That is a midpoint, not a target: there is no evidence that any specific point inside the healthy range is individually optimal.

Timelines assume ~7,700 kcal per kg of body fat. Real progress varies with muscle mass, adherence, and medications.

What does a BMI of 23.4 mean?

Multi-decade studies (notably the NIH-AARP cohort of more than 500,000 adults) link this BMI band to the lowest all-cause mortality.

BMI is a screening tool, not a diagnosis. Two people at 70 kg and 173 cm can have very different body compositions and very different health profiles. Use BMI alongside waist circumference, fitness level, and routine bloodwork.

Waist adds information BMI cannot

Two people can share the same BMI and carry very different amounts of abdominal fat. Waist circumference captures that difference, which is why clinical guidance (NICE CG189, WHO 2008) recommends reading it alongside BMI rather than instead of it.

• Waist-to-height rule: guidance suggests keeping waist below half your height — below 87 cm (34") at 173 cm.
• Sex-specific thresholds: increased risk from 94 cm (37") for men and 80 cm (31.5") for women; substantially increased risk from 102 cm (40") and 88 cm (34.6") respectively. There is no unisex waist threshold.
• What it does not do: waist is another screening measurement. It does not diagnose anything. These waist cut-offs were derived mainly from European-origin populations. WHO notes that equivalent risk occurs at lower waist values in South Asian, Chinese, Japanese and other Asian populations, so they are population-specific rather than universal. The waist-to-height rule above is the more portable check (NICE NG246, for adults with a BMI below 35).

Healthy weight range for 173 cm

The BMI-based healthy weight range for 173 cm tall adults is 55.4–74.8 kg (122–165 lbs).

Precise ±5 kg neighbours at this height

Practical next steps

1. Adult activity guidance is at least 150 minutes of moderate aerobic activity per week.
2. Two strength sessions a week is the standard recommendation for preserving lean mass with age.
3. Waist circumference thresholds are sex-specific: 94 cm for men and 80 cm for women (WHO, 2008), derived mainly from European-origin populations.
4. Routine metabolic bloodwork is a general adult health measure, unrelated to BMI category.

Frequently asked questions