Reforming America's Fiscal Toolkit Act of 2021 or the RAFT Act of 2021 This bill modifies the federal budget process to provide for the establishment of a target for the ratio of the public debt to the estimated gross domestic product (GDP). Specifically, the bill requires congressional budget resolutions to include a recommended ratio of public debt to GDP. In addition, congressional budget resolutions for even-numbered fiscal years must either (1) instruct one or more congressional committees to recommend changes in existing laws necessary to achieve the target ratio, or (2) request the establishment of a Joint Select Committee on Fiscal Responsibility to make the recommendations. The bill also sets forth requirements for (1) establishing the Joint Select Committee on Fiscal Responsibility if it is requested, and (2) considering the recommendations of the joint committee or other congressional committees using expedited legislative procedures in the Senate.