Are online bmi calculators accurate?

Yes: If you enter your correct height and weight into the proper equation or a bmi calculator, the results should be correct. The exact meaning of a particular bmi might be open to interpretation as someone who is very muscular and has only 4% body fat might have a higher bmi than a couch potato who has love handles. For most of us, the bmi is a good indicator of appropriate weight versus overweight.

Yes, but...: The calculator will give you an accurate bmi, but how well that measures your fitness/health is unclear. I've had finely tuned athletes show up as obese according to bmi. If you're concerned about it just check with your doctor.