Elementary school learners are typically highly confident when judging accuracy of their test responses, relatively independent of whether these are correct. While feedback has been shown to improve accuracy of adults' and adolescents' self‐evaluations and subsequent self‐regulation, little is known about beneficial effects for elementary school children. We investigated effects of fine‐grained feedback on fourth and sixth graders' self‐evaluations and restudy selections by presenting them the ideas they were meant to bring up in their test responses. One group received full‐definition feedback standards, whereas the other group received idea‐unit feedback standards. The two types of feedback strongly improved fourth and sixth graders' self‐evaluations for commission errors and for partially correct responses. While restudy selections before feedback were more adaptive for sixth than fourth graders, age differences disappeared after receiving feedback. Findings imply that feedback standards are a suitable tool to calibrate elementary school learners and to support effective self‐regulation.Copyright © 2017 John Wiley & Sons, Ltd.