Yes. It basicly the value of a rental for the duration of your life. Or you can sell the life estate completely. A housing agent can help you figure out the value.
I agree with Attorney Carron.
Another option might be to merge the future interest with your life estate so that the title is fee simple (Absolute ownership with no future interest or life estates). This could be done by either selling the life estate to your friends or buying their future interest from them. This would make the property the most "marketable."
how did you value the remainder interest that you sold? the difference between the full value and the remainder interest should have been the life estate value, work forward from that point, and either sell the life estate to the remaindermen, join with the remainderment to sell the entire house interest, or lease the house (which terminates when you die). good luck.