Hi junghwi,
Thanks for contacting Syncfusion support.
We have similar documented this topic under our UG documentation. Please refer the below documentation for more details regarding this requirement.
Documentation : https://blazor.syncfusion.com/documentation/datagrid/dialog-editing#implement-calculated-column-inside-grid-dialog-editing
Please let us know if you have any concerns.
Regards,
Naveen Palanivel