Tools and methods are used for aligned total knee arthroplasty (TKA) of anatomically or kinematically aligned knee. A block tool system references a distal femoral cut to provide a guide for the tibial cut. The block tool system can be used with the leg in full extension or in flexion. The block tools system includes a femur positioning block, an alignment arm coupled to the femur block, a femural cutting block, a tibial positioning block and a tibial cutting block.