Etabs Mass Summary By Story Better ((link)) Site

You can find this table after running an analysis by navigating to: > Show Tables

Confirm that "Lump Lateral Mass at Story Levels" is enabled to ensure masses are correctly aggregated at each floor for seismic analysis Coordinate System: etabs mass summary by story better

Ensure that the sum of the effective modal masses in the X and Y directions equals at least 90% of the total mass listed in your Story Mass Summary. If they don’t match, your structure is either too flexible (need more modes) or your constraints (rigid diaphragms) are preventing proper mass participation. You can find this table after running an