They found the cities to be separated by one degree of latitude and the distance between them to be 66​2⁄3 miles and thus calculated the Earth's circumference to be 24,000 miles.[9] Another estimate given was 56​2⁄3 Arabic miles per degree, which corresponds to 111.8 km per degree and a circumference of 40,248 km, very close to the currently modern values of 111.3 km per degree and 40,068 km circumference, respectively.[10]