42 lbs to kg conversion result above is displayed in three different forms: as a decimal (which could be rounded), in scientific notation (scientific form, standard index form or standard form in the United Kingdom) and as a fraction (exact result). Every display form has its own advantages and in different situations particular form is more convenient than another. For example usage of scientific notation when working with big numbers is recommended due to easier reading and comprehension. Usage of fractions is recommended when more precision is needed.
If we want to calculate how many Kilograms are 42 Pounds we have to multiply 42 by 45359237 and divide the product by 100000000. So for 42 we have: (42 × 45359237) ÷ 100000000 = 1905087954 ÷ 100000000 = 19.05087954 Kilograms
So finally 42 lbs = 19.05087954 kg