Highest salary at Town of Grantham in year 2021 was $90,028. Number of employees at Town of Grantham in year 2021 was 21. Average annual salary was $50,794 and median salary was $51,400. Town of Grantham average salary is 8 percent higher than USA average and median salary is 18 percent higher than USA median salary. From 2020 to 2021, the median salary increased 7.7 percent.