Overweight Calculator - BMI 25, 30, 35, 40 Cutoffs

An overweight calculator on this site still computes adult BMI = kg / m², then highlights whether that number sits at or above the WHO cutoffs people actually search for: ≥ 25 overweight, ≥ 30 obesity class I, ≥ 35 class II, and ≥ 40 class III. It also reports how many kilograms sit above or below the 24.9 boundary at the same height. The default inputs are 180 cm and 90 kg. Height squared is 1.8 × 1.8 = 3.24 m². BMI = 90 / 3.24 ≈ 27.78, which is overweight, not obesity class I. The normal-band maximum is 24.9 × 3.24 = 80.676 kg, so 90 − 80.676 ≈ 9.3 kg above that line.

That is a screening arithmetic, not a disease name. Clinical obesity is not identical to a BMI cutoff. Blood pressure, glucose, lipids, waist, sleep apnea, and family history can disagree with the band. This page therefore labels the WHO class as a category, not a diagnosis, and it is not medical advice.

The BMI calculator shows the full ladder including thinness grades. This page emphasizes the overweight and obesity cutoffs and the kilogram gap versus 24.9 × m². The healthy weight calculator needs height only and lists the 18.5–24.9 kilogram band without today’s weight. Use the tool that matches the question.

Scope is adult and non-pregnant. Children need percentiles. Pregnancy needs obstetric guidance. Some health systems apply lower action thresholds (often 23 and 25) for people of Asian ancestry. This calculator reports the global WHO adult table and does not silently switch ethnic cutoffs.

1. Choose metric (centimetres and kilograms) or imperial (feet, leftover inches, and pounds).
2. Enter current standing height and a recent weight.
3. Read BMI, the highlighted WHO class, and kilograms above or below 24.9 × m². Copy the result if you need a record.
4. If you train with high lean mass, read the athlete note before treating BMI ≥ 25 as excess fat. Inputs stay in this browser for up to 30 days and are never uploaded.

Copy/Clear, fullscreen, and a resizable split match the other health tools on this site. Inputs expire from localStorage after 30 days. Nothing is uploaded. If you change units, the imperial fields are a separate state (5 ft 11 in / 198 lb as a rough cousin of 180 cm / 90 kg), not a live conversion of the metric default. Read the highlighted class after you finish typing, not while a field is blank.

The 24.9 gap uses the same m² as BMI, so it moves only when height moves. Two people at 90 kg are not “equally” above the line if one is 165 cm and the other is 190 cm. Always read the kilogram gap next to the class name. That pair is the whole product: a WHO label plus a distance to 24.9 × m². Athletes still get an honest asterisk: BMI ≥ 25 can be muscle. That disclaimer is the difference between a screening page and a fat-shaming page.

Convert 180 cm to 1.80 m. Square it: 3.24 m². Divide 90 kg by 3.24: BMI = 27.777…, displayed as 27.78. WHO overweight starts at 25.0 and runs through 29.9, so 27.78 is unambiguously overweight on that table and still below obesity class I. The matching 24.9 ceiling is 24.9 × 3.24 = 80.676 kg. The gap 90 − 80.676 = 9.324 kg is shown as about 9.3 kg above the normal-band max. If someone weighed 75 kg at the same height, BMI would be 23.15 (below overweight) and the page would report about 5.7 kg still below that 80.676 kg line.

Imperial check: 5 ft 11 in is 71 inches ≈ 180.34 cm. 198 lb is about 89.8 kg. Small discrepancies versus the metric default come from rounding feet-and-inches, not from a different definition of BMI. This page converts imperial entries to SI before dividing.

Class edges are administrative cliffs. BMI 29.9 is still overweight; 30.0 is class I. BMI 34.9 is class I; 35.0 is class II. BMI 39.9 is class II; 40.0 is class III. A tenth of a BMI point is not a sudden change in physiology. The kilogram gap versus 24.9 is often more intuitive than the class name: it answers “how far is the scale from the top of the WHO normal band at this height?”

BMI cannot tell fat mass from muscle or bone. Rugby forwards, American football linemen, heavyweight weightlifters, and some sprinters routinely sit above 25 or 30 with body-fat percentages that a DEXA scan would not call obese. Treating that BMI as a fat verdict is the most common misuse of an overweight calculator. This page repeats the disclaimer next to the number because search traffic still treats ≥ 25 as a moral grade.

The other failure mode is the sedentary adult at BMI 24.8 with a large waist and little muscle. That person can have more visceral fat than the 28-BMI athlete. Waist circumference (often 102 cm / 40 in in men and 88 cm / 35 in in women as crude metabolic-risk flags in some guidelines) and a Navy body-fat estimate add information BMI cannot see. Even those are still estimates. Clinical assessment beats a web form.

Older adults can lose height (vertebral compression) and thereby inflate BMI without gaining fat. Edema, casts, and ascites inflate weight independently of adipose tissue. If the body is not a textbook cylinder, do not treat 27.78 as destiny.

Pediatric overweight uses BMI percentiles, not adult WHO 25 / 30 / 35 / 40. A child with BMI 22 may be high on a growth chart while an adult with BMI 22 is typical. This tool will still divide kg by m² if you type a short height, but the class labels remain adult WHO labels.

Pregnancy changes weight independently of adiposity. Gestational guidance starts from pre-pregnancy BMI, not from a third-trimester scale reading labeled “overweight.” Do not use this calculator to classify a pregnancy.

Several Asia–Pacific statements recommend action from BMI 23 and obesity from 25 for some East and South Asian groups, because diabetes risk can rise at a lower BMI than in many European cohorts. This calculator does not auto-apply those cutoffs. If you are using a clinic that does, map 23 and 25 yourself rather than assuming the WHO 25/30 lines are universal biology.

Healthy weight on this site is the kilogram interval that keeps BMI in 18.5–24.9 at a given height - at 180 cm, 59.94– 80.68 kg. That is why the default 90 kg example is about 9.3 kg above the top of the band. Compute the band without today’s weight on the healthy weight calculator. Ideal-body-weight formulas are a different family entirely; compare Devine and friends on the ideal weight calculator. They are not BMI 25.

Energy needs are yet another question. BMI class does not tell you how many calories to eat. Estimate BMR with the BMR calculator and daily expenditure with the calorie calculator. Those are planning estimates, not orders, and they are not a treatment plan for obesity.

If the number is below 18.5, this page still shows “below overweight” rather than thinness grades. For mild, moderate, and severe thinness, use the underweight BMI calculator or the full BMI calculator. Neither diagnoses an eating disorder.

Quetelet’s ratio became a public-health cutoff table because agencies needed a cheap field metric. Overweight at 25 and obesity at 30 are convention, not a law of physics. Search traffic still clusters on “am I overweight,” “BMI 27,” and “how many kg overweight.” The honest default answer is: 180 cm and 90 kg is BMI 27.78, overweight on the WHO table, about 9.3 kg above 80.676 kg. How to calculate it is kg/m². What to do about fat, muscle, or medication is clinical work this page will not perform.

Stigma is a documented harm of BMI-only conversations. Crash diets, weight-cycling, and using a calculator as self-punishment are not what a screening cutoff is for. If food or weight thoughts are taking over your life, contact a clinician or a local eating-disorder resource. A BMI of 27 cannot diagnose an eating disorder, and a BMI of 22 cannot rule one out.

Worked extras: 180 cm and 100 kg → BMI 30.86 (class I), 19.3 kg above 80.676. 180 cm and 115 kg → 35.49 (class II). 180 cm and 130 kg → 40.12 (class III). 165 cm and 80 kg → 29.38 (overweight). 165 cm and 82 kg → 30.12 (class I). 190 cm and 90 kg → 24.93 (still just under 25, about 0.2 kg under the 24.9 max of 89.89 kg). Those examples show how a couple of kilograms move a shorter adult across a cutoff that a taller frame would barely notice.

“Pre-obesity” is a synonym some WHO materials use for the 25.0–29.9 band. This page still prints “overweight” because that is the word most searchers type, then notes the synonym in the class detail. Neither word is a diagnosis. Class I / II / III likewise replace older “obese / severely obese / very severely obese” phrasing in many teaching charts. The cutoffs did not change when the class names did.

Kilograms to the next class can be more useful than the class name. At 180 cm, class I begins at 30 × 3.24 = 97.2 kg, class II at 35 × 3.24 = 113.4 kg, class III at 40 × 3.24 = 129.6 kg. The default 90 kg example is 7.2 kg short of class I and 9.3 kg past the 24.9 line. Someone at 96 kg is still overweight; 98 kg is class I. Those two kilograms are a rounding error on a weekly scale and a category change on a form. Do not treat the form as physiology.

Waist-to-height and waist circumference remain the usual companions when BMI ≥ 25 is unsurprising (strength sports) or when BMI < 25 looks “fine” on paper. This page does not collect waist. It will not estimate body fat from BMI alone. If the question is adipose tissue, use a composition method or a clinic; if the question is “where does 90 kg sit on the WHO adult table at 180 cm,” the answer is 27.78, overweight, about 9.3 kg above 80.676 kg.

More defaults people type, still screening only: 175 cm and 85 kg → BMI 27.76, overweight, 8.74 kg above 76.26 kg. 170 cm and 80 kg → 27.68, overweight, 8.04 kg above 71.96 kg. 160 cm and 70 kg → 27.34, overweight, 6.26 kg above 63.74 kg. 185 cm and 90 kg → 26.30, overweight, 4.78 kg above 85.22 kg. 190 cm and 110 kg → 30.47, class I, 20.11 kg above 89.89 kg. 200 cm and 120 kg → 30.00, class I on the nose, 20.4 kg above 99.60 kg. Same “overweight” word, very different kilogram gaps. That is why this page prints both the class and the 24.9 distance instead of stopping at a color-coded badge.

After you have the class, composition and training tools answer different jobs: lean body mass, one-rep max, running pace, and calories burned. This page only divides mass by height squared and points at 25, 30, 35, and 40.