How much you must repay depends on the types of debt you have. Here are the general guidelines:
Bankruptcy fees. You must pay 100% of the bankruptcy filing fees, trustee commissions, and your bankruptcy attorney's fees.
Priority debts. You must pay 100% of the following debts: child and spousal support arrears owed to the parent or child; most tax debts except those first due at least three years prior to your bankruptcy filing; wages, salaries, or commissions you owe to employees up to a certain limit; and contributions you owe to an employee benefit fund.
Secured debts. If you want to keep your home or car (or other secured property), you will have to pay 100% of the amount you are behind on the loan. You also have to pay 100% of debt secured because of a tax lien.
Unsecured debts. This is the wild card category. You will pay anywhere between 0% and 100% of the amount you owe, depending on your disposable income, the length of your repayment plan, and the total value of what your creditors would have received had you filed under Chapter 7 bankruptcy. The amount you will pay is generally equal to the value of your property that isn't exempt under the bankruptcy exemption laws (the property you would be likely to lose in a Chapter 7 bankruptcy). To learn more about what you must pay in a Chapter 13 bankruptcy, see Nolo's article Your Obligations Under a Chapter 13 Bankruptcy Plan.