Etabs Mass Summary By Story May 2026

In ETABS, the Mass Summary by Story is one of the most critical outputs for structural engineers. It provides a concise breakdown of how weight is distributed across the height of a building—a factor that directly dictates seismic forces and dynamic behavior.

Part 2: Accessing the ETABS Mass Summary by Story

You can access this summary in three ways: etabs mass summary by story

Open your ETABS model.
Go to the "Analyze" menu.
Select "Mass Summary" from the drop-down menu.
In the "Mass Summary" dialog box, select the "By Story" tab.

Metric: 1 kN-force = 1 / 9.81 = 0.10197 kN·s²/m
Imperial: 1 kip-force = 1 / 386.4 = 0.002588 kip·s²/in

Mass X & Mass Y: These represent the total mass considered for horizontal motion in the X and Y directions. In most cases, these values are identical unless you have assigned specific directional mass properties. In ETABS, the Mass Summary by Story is

1. Introduction

Modern building codes (e.g., ASCE 7, IBC, Eurocode 8) require dynamic analysis for irregular or tall structures. Before running modal or response spectrum analysis, engineers must verify that the mass model is correct. The ETABS Mass Summary by Story serves as the primary quality control tool to ensure that the total seismic weight ($W$) matches code expectations and that mass is distributed logically over the building height. Open your ETABS model

When you open the table, you will see several key headings. Understanding these is vital for an accurate peer review or design check: Story: The specific level of the building.

To access the report, navigate to:Analysis Results > Structure Results > Mass Summary > Mass Summary by Story 📊 Understanding the Data Columns Story: The specific floor level. Mass X / Mass Y: Total mass in horizontal directions.