Estimating lengths is an important skill for coping with many everyday situations and therefore a goal of math lessons is for children to estimate as accurately as possible. In order to achieve this goal, learning opportunities should be chosen for the mathematics classroom that develop the length estimation competence as fully as possible. The article aims at (a) analyzing the extent to which German textbooks for elementary school cover the different characteristics of estimation tasks and (b) how the share of tasks matches students’ competence profiles. Four German textbook series are analyzed in regard of the task characteristics. It shows that some tasks are underrepresented (such as estimating the length of objects that are not physically present). In a second analysis, the results from the textbook analysis are compared with the competence profiles of 450 German third and fourth grade students. It indicates that some distributions of task characteristics match the students’ competence profiles (e.g. the majority of tasks holds physically present objects and the German students estimate the lengths of physically present objects significantly more accurate than objects that are not physically present) while there is a mismatch for other characteristics.