Grantham is a distinctive boys' name in United States, ranking #7565 in 1997 with 7 recorded births. This places Grantham in the bottom 30% of ranked US boys' names for the year. Its actual usage is classified as Rare. The name reached its all-time peak in 2003 with 12 births ranking #6001. Since 1996, the popularity has decreased by 30.0%. In 1997, approximately 1 in every 269,299 boys born was named Grantham. FALLING Recent data shows the name is currently falling.