BMI Calculator With Chart — Find Your Row

A chart tells you which band you are in. What it hides is how far into that band you are — and whether you are two pounds from the edge or thirty. Calculate the number first, then use the rest of this page to place it.

Your number, then your row

Adults are sorted into four bands by the NHLBI: under 18.5, 18.5 to 24.9, 25.0 to 29.9, and 30 and above. Reading a chart backwards — scanning for your weight until a row matches — gets you the label, but it stops there. Reading it forwards, from your calculated value, tells you the label and the distance.

Take someone 5 ft 10 in at 190 lb (86 kg, 1.78 m): 703 × 190 ÷ 70² = 27.3. A chart would say overweight and move on. The number says overweight and roughly in the middle of that band — about 16 pounds above where it begins and 19 below where the next one starts.

The full lookup, height by height, is on the BMI chart page. This one is about what the chart cannot show you.

What a single point weighs

One BMI point is not one amount of weight. Because height is squared in the denominator, the same point costs more pounds the taller you are:

Height	1 BMI point
5 ft 0 in	5.1 lb
5 ft 2 in	5.5 lb
5 ft 4 in	5.8 lb
5 ft 6 in	6.2 lb
5 ft 8 in	6.6 lb
5 ft 10 in	7.0 lb
6 ft 0 in	7.4 lb
6 ft 2 in	7.8 lb

Each figure is in² ÷ 703, the weight that moves BMI by exactly 1.0 at that height. It explains two things at once: why the healthy band spans 39 pounds for a short adult and over 50 for a tall one, and why a tall person’s number barely twitches at a five-pound swing while a short person’s moves almost a full point.

Distance to the next line

Once you know what a point costs, the useful question stops being “which row am I in” and becomes “how far from the edge”. Subtract your BMI from the boundary above or below, multiply by the pounds-per-point figure for your height, and you have the answer in units a bathroom scale uses.

At 5 ft 6 in with a BMI of 25.4: (25.4 − 25.0) × 6.2 = about 2.5 pounds back into the healthy band. That is a meal and a glass of water, which is the honest way to read a result that close to a line — the category changed, the body did not.

When the two disagree

A chart rounds to whole pounds, so its edges sit a fraction off the exact cutoff, and different charts round in different directions. If a table calls you overweight and a calculator says 24.9, neither is broken; you are inside the rounding. That is a sign to stop reading the label and start looking at waist, blood pressure and labs instead.

For how age changes the reading, see ideal BMI by age; for what the number does and does not predict about the heart, see BMI and heart disease risk.

This content is informational and does not replace evaluation by a health professional.