To provide a device for estimating tension of a rolled stock with which the tension of the rolled stock is estimated with high accuracy and a looperless controller for a rolling mill using the same when tension control of the tension of the rolled stock between respective stands of a tandem mill is executed without using a looper.

At the time of estimating the tension of the rolled stock between the stands of the tandem mill, this device is provided with a rolling load detecting means 4 for detecting the rolling load at the stand where at least either front tension or back tension is taken as an object of estimation, rolling torque detecting means 6 for detecting the rolling torque of the stand, influence coefficient setting means 15A for setting influence coefficients necessary to estimate the tension of the rolled stock and tension estimating means 16A for estimating at least either front tension or back tension at the stand based on the detected rolling load, rolling torque and set influence coefficient. In such a case, as the influence coefficient necessary to estimate the tension, at least the influence coefficient α of front tension to the rolling load and the influence coefficient β of back tension to the rolling load are included.