What formula is used to calculate round bar weight?

The formula is: Weight = (π ÷ 4) × Diameter² × Length × Density. This gives the volume of a cylinder which is then multiplied by the material density to get mass.

How much does a 1 inch round bar weigh?

A 1 in (25.4 mm) carbon steel round bar weighs about 3.98 kg per meter, or roughly 2.67 lb per foot: (π ÷ 4) × 0.0254² × 1 × 7850. Multiply by your length for the total.

What is the density of carbon steel?

Carbon steel (mild steel) has a density of approximately 7850 kg/m³ (0.284 lb/in³), which is the standard value used in most structural steel calculations.

Can I calculate weight for multiple bars at once?

Yes. Enter the quantity in the Quantity field and the calculator will multiply the single bar weight by that number to give total weight.

Does this work for metric and imperial units?

Yes. You can enter dimensions in millimeters, meters, inches, or feet. Select your preferred unit from the dropdown next to each input field.

What is the difference between stainless 304 and 316?

Both grades have nearly identical density (7930 kg/m³ for 304 vs 8000 kg/m³ for 316). The difference is in corrosion resistance — 316 contains molybdenum for better resistance to chlorides.

How accurate is this calculator?

Results are accurate to the theoretical weight based on nominal dimensions and standard densities. Actual bar weight may vary slightly due to manufacturing tolerances and surface finish.

Steel Round Bar Weight Calculator

Name: Steel Round Bar Weight Calculator
Availability: InStock
Author: Nham Vu

Enter diameter, length, and material to instantly calculate the weight of a round bar in kg or lbs.

Bar Dimensions

Diameter

Length

Material

Quantity (bars)

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.

Common Material Densities

Material	kg/m³	lb/in³
Carbon Steel	7850	0.284
Stainless 304	7930	0.286
Stainless 316	8000	0.289
Cast Iron	7200	0.260
Copper	8960	0.324
Brass	8500	0.307
Aluminum	2700	0.098
Titanium	4500	0.163

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Summary

Enter diameter, length, and material to instantly calculate the weight of a round bar in kg or lbs.

How it works

Enter the bar diameter in millimeters or inches.
Enter the bar length in meters, feet, or millimeters.
Select the material from the dropdown to apply the correct density.
Optionally enter a quantity for multiple bars.
The calculator applies the formula Weight = (π/4) × D² × L × ρ and displays the result in kg and lbs.
Use the Copy button to copy the result to your clipboard.

Use cases

Estimating steel weight for structural engineering projects.
Calculating material costs for machining and fabrication jobs.
Comparing weights of different metals for product design.
Freight and shipping weight estimates for metal orders.
Checking weight limits on lifting equipment.
Bill of materials (BOM) preparation for manufacturing.

Frequently Asked Questions

Last updated: 2026-06-10 · Reviewed by Nham Vu