Round Bar Weight Calculator
This round bar weight calculator finds the weight of a solid round bar from its diameter and length. Enter them and the round bar weight calculator returns the total weight and the weight per meter. As a steel round bar weight calculator it uses the standard steel density, so the result matches mill tables for every common bar size.
Results
The Round Bar Weight Calculator is part of our Weight collection. Browse more weight to size, convert, and check your work alongside this tool.
What the round bar weight calculator shows
A round bar is a solid steel cylinder, and the round bar weight calculator finds its weight from the diameter and the length. It works out the round cross section, multiplies by the length for the volume, and multiplies by the steel density for the weight. As a steel round bar weight calculator it returns the weight per meter and the total, so you can order by the kilogram or the ton.
The formula for round bar weight
The formula for round bar weight comes from the circular area and the steel density, which reduces to a tidy shortcut:
d is the diameter in millimeters, and 162 folds in the steel density of about 7,850 kg per cubic meter. Multiply the weight per meter by the length for the total. This round bar weight calculation formula is why a 20 mm bar always works out near 2.47 kg per meter.
Round bar weight calculator example
A 20 mm steel round bar, 1 m long. The round bar weight calculator applies the formula:
So a 1 m length of 20 mm round bar weighs about 2.47 kg. Change the diameter and the round bar weight calculator returns a new weight at once.
How to use the round bar weight calculator
Enter the bar diameter in millimeters and the length, then the round bar weight calculator returns the total weight and the weight per meter. Use the nominal diameter stamped on the bar. For a full order, run each diameter through the round bar steel weight calculator once and add the totals, since weight climbs steeply with size.
Reading the round bar weight calculator result
The weight per meter is the unit weight for that diameter; the total is that value times length and quantity. Because weight follows the diameter squared, doubling the size nearly quadruples the weight, so large bars get heavy fast. Order by total weight, since steel is priced by the kilogram or ton, and confirm the figure against a delivery note. For stainless, the density is a touch higher, so an ss round bar weight calculator runs slightly heavier than mild steel.
When to use the round bar weight calculator
- Pricing an order by weight with the round bar weight calculator
- Checking a delivery, the wt of round bar against a note
- Building a cutting list with a steel round bar weight calculator
- Comparing sizes with a round bar weight chart
Common round bar weight calculator mistakes
- Using radius for diameter. The formula needs the full diameter; using the radius makes the weight far too small.
- Wrong material density. Set stainless or aluminum density when the bar is not mild steel.
- Forgetting cut waste. Add a small allowance for offcuts after the round bar weight calculation.
Tips for round bar takeoffs
- Enter the nominal diameter stamped on the bar.
- Order by weight, since steel is priced by the kilogram or ton.
- Switch the density for stainless or aluminum rod.
MS round bar weight calculation and steel round bar weight calculator
The ms round bar weight calculation is the weight of a cylinder written for bar sizes. Take the round area, pi over four times the diameter squared, multiply by the length for the volume, and multiply by the steel density of about 7,850 kg per cubic meter for the mass. Fold the density and the unit changes together and it collapses to d² divided by 162, with d in millimeters and the answer in kilograms per meter, which is exactly what a steel round bar weight calculator uses. Because the diameter is squared, weight climbs fast: a round bar steel weight calculator shows a 32 mm bar at over 6 kg per meter, ten times a 10 mm bar, even though the diameter only tripled. Grade barely matters for mild and structural steel, since they share the same density, so the wt of round bar is set by size, not strength.
SS round bar weight calculator for stainless
Material density is the one thing that shifts the result. An ss round bar weight calculator, or stainless steel round bar weight calculator, uses a density near 8,000 kg per cubic meter, a few percent above mild steel, so the same diameter runs slightly heavier. An aluminium round bar weight calculator sits at the other end, near 2,700, so an aluminum bar of the same size weighs roughly a third of steel, which is why aluminum round rod is common where weight matters. A round rod weight calculation for any of these keeps the d² divided by 162 shape for steel, and simply swaps the constant for other metals. Set the density to match the bar, and the round bar weight chart and this calculator agree with the mill data.
Round bar weight chart
Steel round bar weight per meter by diameter, from the d² ÷ 162 formula in this round bar weight chart:
| Diameter | Weight per meter | Weight per 6 m |
|---|---|---|
| 10 mm | 0.62 kg/m | 3.72 kg |
| 12 mm | 0.89 kg/m | 5.34 kg |
| 16 mm | 1.58 kg/m | 9.48 kg |
| 20 mm | 2.47 kg/m | 14.82 kg |
| 25 mm | 3.85 kg/m | 23.10 kg |
| 32 mm | 6.31 kg/m | 37.86 kg |
Round Bar Weight Calculator FAQ
What is the formula for round bar weight?
The formula for round bar weight is weight per meter equals d² divided by 162, with d the diameter in millimeters. The round bar weight calculator applies it and multiplies by length for the total.
What does a 20 mm round bar weigh?
About 2.47 kg per meter for mild steel, from 20² divided by 162. That is the steel round bar weight calculator value mill tables list.
Where does 162 come from?
It folds the steel density of 7,850 kg per cubic meter into the round area. The round bar weight calculation formula d² divided by 162 is the tidy result.
Does it work for stainless and aluminum?
Yes, with the right density. An ss round bar weight calculator runs a little heavier than mild steel, and an aluminium round bar weight calculator about a third as heavy.