paying off a loan

So let me start by saying any help is greatly appreciated. Right now money is a little tight after bills. I make enough to pay them every month but not much left over for things like my 401k. Not broke, bills are paid and do save up weekly. I'm 24 and make about 60k per year on average. My problem is having some small payments every month to different things that add up quickly. Furniture will be payed off next week interest free and that'll save me $200 a month. In about 5 months I'll be done with a $140/month payment. That leaves me with a monthly $99 loan payment. I borrowed $2500 and have a 3 year payment plan. Needed it to help consolidate debt with very high interests rates from some poor decisions before I got my current job. Right now I pay the minimum and have about 2 years left of payments. I wanna try and pay it off faster than that. If I pay say $20 extra a month how much time would it cut off. Willing to pay more than that if it helps pay it off quicker.