In order to simplify diagnostics for doctors with scales without automatic BMI calculation, seca has launched the Seca 491 BMI calculator. Once height in metres and weight in kilogrammes have been entered, it automatically calculates BMI at the touch of a button. Entries can also be made in pounds (lbs), feet (ft) or inches (in).

The BMI calculator can also be used as a normal pocket calculator. It has all four basic calculation functions and an eight-digit display. Energy is provided by a solar cell and a battery in case there is insufficient light in the room to allow solar-powered operation. The calculator is about 55 mm wide by 97 mm high and 10 mm deep. The seca 491 is also indispensable in residential care, as it is recommended that care documentation should include a record of BMI.