Body Mass Index (BMI) is the preferred method of measurement for doctors and researchers studying obesity. The formula used to calculate an individual's BMI is weight (in kilograms) divided by height (in meters) squared.

BMI differs due to age and sex

Although it is correlated with body fat, its implications differ according to age and sex. Women generally have more body fat than men, for example. Furthermore, a muscular athlete and an out-of-shape person can have the same BMI score. Older people tend to have more body fat than younger adults with the same BMI. Interpretation of the BMI scores, therefore, is not an exact science.

What BMI score should you aim for?

In adults over 20 years of age, the BMI chart shows BMI scores of less than 18.5 as underweight, while the normal range should be between 18.5 and 24.9. Those with scores falling between 25.0 and 29.9 are deemed overweight, while those at 30.0 and above are classified as obese. It is important to note that BMI is only one indicator of relative health or risk for disease. With weight control and exercise, BMI scores can be brought into the healthy range, and overall health can be considerably improved.

BMI (kg/m2)	19	20	21	22	23	24	25	26	27	28	29	30	35	40
Height (in.)	Weight (lb.)
58	91	96	100	105	110	115	119	124	129	134	138	143	167	191
59	94	99	104	109	114	119	124	128	133	138	143	148	173	198
60	97	102	107	112	118	123	128	133	138	143	148	153	179	204
61	100	106	111	116	122	127	132	137	143	148	153	158	185	211
62	104	109	115	120	126	131	136	142	147	153	158	164	191	218
63	107	113	118	124	130	135	141	146	152	158	163	169	197	225
64	110	116	122	128	134	140	145	151	157	163	169	174	204	232
65	114	120	126	132	138	144	150	156	162	168	174	180	210	240
66	118	124	130	136	142	148	155	161	167	173	179	186	216	247
67	121	127	134	140	146	153	159	166	172	178	185	191	223	255
68	125	131	138	144	151	158	164	171	177	184	190	197	230	262
69	128	135	142	149	155	162	169	176	182	189	196	203	236	270
70	132	139	146	153	160	167	174	181	188	195	202	207	243	278
71	136	143	150	157	165	172	179	186	193	200	208	215	250	286
72	140	147	154	162	169	177	184	191	199	206	213	221	258	294
73	144	151	159	166	174	182	189	197	204	212	219	227	265	302
74	148	155	163	171	179	186	194	202	210	218	225	233	272	311
75	152	160	168	176	184	192	200	208	216	224	232	240	279	319
76	156	164	172	180	189	197	205	213	221	230	238	246	287	328