40 light year to km 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 Kilometers are 40 Light Years we have to multiply 40 by 47303652362904 and divide the product by 5. So for 40 we have: (40 × 47303652362904) ÷ 5 = 1.8921460945162E+15 ÷ 5 = 3.7842921890323E+14 Kilometers
So finally 40 light year = 378429218903232 km
