A shaft encoder arrangement (1) provides high precision and at the same time can be used in harsh environments and is simple to mount. The shaft encoder arrangement (1) has at least one measuring device (2) for determining a rotary position of a rotatable body, for example, of a shaft (4) of a motor (6), with at least one magnetic dimensional scale (7) that can be mounted on the body and at least one sensor device (8) for scanning the magnetic dimensional scale (7). The sensor device (8) lies at least partially within a space (14) enclosed by the magnetic dimensional scale (7), and the magnetic dimensional scale (7) is enclosed by a circumferential magnetic shield (12). The magnetic shield permits use of the shaft encoder arrangement (1) even in harsh environments and even in strong magnetic interference fields.