Iron Round Bar Weight Calculator

Enter diameter, length, and iron type to instantly calculate the weight of an iron round bar in kg and lbs.

Bar Dimensions

Formula Reference

W = (π / 4) × D² × L × ρ

Where D = diameter (m), L = length (m), ρ = density (kg/m³), W = weight (kg).

Enter dimensions on the left and click Calculate.

Iron Type Densities

Iron Type kg/m³ lb/in³
Cast Iron (general) 7200 0.260
Gray Cast Iron 7100 0.257
Ductile Cast Iron 7300 0.264
Wrought Iron 7750 0.280
Carbon Steel (ref.) 7850 0.284
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Summary

Enter diameter, length, and iron type to instantly calculate the weight of an iron round bar in kg and lbs.

How it works

  1. Enter the bar diameter in millimeters, centimeters, or inches.
  2. Enter the bar length in meters, millimeters, feet, or inches.
  3. Select the iron type — cast iron or wrought iron.
  4. Optionally enter the quantity of bars for a total weight.
  5. Click Calculate Weight to apply the formula W = (π/4) × D² × L × ρ.
  6. Copy the result with the Copy button for use in reports or spreadsheets.

Use cases

Frequently Asked Questions

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Last updated: 2026-05-23 · Reviewed by Nham Vu