I am trying to calculate the rise in sea level if all the ice on landmass were to melt. I have some facts and figures but I'm guessing not all.

the total of the earth's landmass is roughly 148 million km^2 and ice is on 10% (14.8 million km^2). I have read the answer could be around 70 meters if all the ice on land melts but I'm having trouble getting there mathematically from the stats I've got. any help would be appreciated.