Both federal loans and private loans can be consolidated, but due to differences in how interest rates are calculated, it isn’t always a good idea to consolidate them together.Federal consolidated loans have a fixed-interest rate for the life of the loan that is based on the average of the interest rates of the consolidated loans.A bank or a credit card company will not be inclined to offer you a good deal with less than a stellar credit score (such as the 500s), so there are some nasty tactics to look out for if you opt for a finance company.
Nor is it a good idea to combine them under a private loan, as your interest rates will most likely rise [source: Fin Aid].
Private consolidated loans base the interest rate on your credit score.
If your credit score improved significantly since you first obtained the loans, you may be able to get a lower interest rate on a consolidated loan.
If interest rates are decreasing, you might be able to secure a lower fixed-interest rate for the life of your loan by waiting a bit.
On the flip side, if interest rates are expected to rise, locking in a fixed rate now could be a smart move.