There are variables that impact the answer. Such as where you live. In AZ you would need more acreage than you would in someplace like eastern GA. Here, in the flat, well watered deep South I can keep 2 horses on a 4 acre section of the field and they keep it well grazed to the point that it doesn't really need mowing. While if I put them on a 6 acre area they don't eat it down quite as much and i might need a light mowing a couple of times a month. I personally would probably keep my numbers down to 3, but certainly no more than 4 for 10 acres, but that's just me since I prefer to always have a bit more grass than needed since my horses lived completely on grazing during the grass growing seasons here (which is April through Oct....it's warm, hot, and wet most of the year so there is an over abundance of vegetation growth)Was wondering how many horses I can have on 7 acres I have a lot of grass on it. I already have 2 horses on it, how many more can I have for it to be a decent amount of grass for them?