Free Metal Weight calculator
Find out exactly what a piece of metal weighs before you order or lift it. Pick a shape — plate, round bar, square bar, flat bar, tube or hex — enter its dimensions, and choose from steel, stainless, aluminum, copper, brass or titanium. The calculator returns the weight in both pounds and kilograms, the cross-sectional area, and a side-by-side comparison of the same piece in every metal — updated live, as you type.
On this page14 sections
| Metal | Weight (lb) | Weight (kg) |
|---|---|---|
| Carbon steel | 32.07 | 14.55 |
| Stainless | 32.69 | 14.83 |
| Aluminum | 11.03 | 5.00 |
| Copper | 36.61 | 16.61 |
| Brass | 34.72 | 15.75 |
| Titanium | 18.41 | 8.35 |
Same shape and dimensions in each metal, ranked by density. Nominal densities (lb/in³): steel 0.2836, stainless 0.289, aluminum 0.0975, copper 0.3237, brass 0.307, titanium 0.1628.
Real weight varies with mill tolerance, alloy grade and coating. How accurate is this?
Results are estimates. Consult a professional.
How the metal weight calculator works
Metal is priced and shipped by weight, but you buy it by shape and size. This metal weight calculator bridges the two with one rule from materials engineering: weight equals the cross-sectional area of the stock, times its length, times the density of the metal. Pick a shape, enter its dimensions, choose the metal, and it returns the weight in both pounds and kilograms.
What the result really tells you
The weight figure is the shipping and handling weight of the raw stock — what the mill quotes, what the freight is priced on, and what tells you whether one person can carry the piece. It is not the finished part weight: any holes, cuts, or machining you do later only remove metal, so the calculator gives the heaviest the piece will ever be.
Cross-section formula for each metal shape
Every shape shares the same volume-and-density math. Only the cross-sectional area changes. Get the area right and the weight follows. Here is the area formula behind each stock shape the calculator supports, with all dimensions in inches.
| Shape | Cross-sectional area | Dimensions you enter |
|---|---|---|
| Plate / sheet | width × thickness | length, width, thickness |
| Round bar | (π ÷ 4) × diameter² | diameter, length |
| Square bar | side² | side, length |
| Flat bar | width × thickness | width, thickness, length |
| Round tube / pipe | (π ÷ 4) × (OD² − ID²) | outer diameter, wall, length |
| Hex bar | 0.866 × across-flats² | across-flats, length |
OD is the outer diameter and ID = OD − 2 × wall thickness. The hex factor 0.866 is √3 ÷ 2, the area of a regular hexagon measured across its flats.
Why the tube formula subtracts a second circle
A round tube is a solid bar with a hole bored through it. Its metal area is the full outer circle minus the hollow inner circle: (π ÷ 4) × (OD² − ID²). Because the wall sits on both sides, the inner diameter is the outer diameter minus twice the wall thickness. The same logic gives the weight of pipe, the hollow cousin of round bar.
Density of common metals
Density is the only number that changes when you switch metals while keeping the same shape and size. It is the mass packed into each unit of volume, and it is why a copper bar and an aluminum bar of identical dimensions can differ in weight by more than three to one. These are the nominal densities the calculator uses, shown in both the unit US suppliers quote (pounds per cubic inch) and the metric unit (kilograms per cubic metre).
| Metal | Density (lb/in³) | Density (kg/m³) |
|---|---|---|
| Carbon / mild steel | 0.2836 | 7,850 |
| Stainless steel | 0.2890 | 7,999 |
| Aluminum | 0.0975 | 2,699 |
| Copper | 0.3237 | 8,960 |
| Brass | 0.3070 | 8,498 |
| Titanium | 0.1628 | 4,506 |
Nominal values per AmesWeb and The Engineering ToolBox. The kg/m³ column is derived from the lb/in³ figure (1 lb/in³ = 27,679.9 kg/m³), so the two units never drift apart. Specific alloys vary slightly — stainless 304 ≈ 7,930 and 316 ≈ 7,990 kg/m³; confirm against your mill certificate for precision work.
A worked example using the metal weight calculator
Maria needs to know the weight of a single 2 in diameter carbon-steel round bar cut to 36 in (3 ft) so she can quote freight and decide whether it is a one-person lift. She has the diameter, the length and the metal — everything the formula needs.
Step 1 — Find the cross-sectional area
Round bar area is π ÷ 4 × diameter². So (π ÷ 4) × 2² = (π ÷ 4) × 4 = 3.1416 in².
Step 2 — Multiply by the length for volume
3.1416 × 36 = 113.10 in³. That is the solid volume of metal in the bar.
Step 3 — Multiply by density for the weight
Carbon steel is 0.2836 lb/in³, so 113.10 × 0.2836 = 32.07 lb. Converting, 32.07 × 0.4536 = 14.55 kg.
Metal weight reference chart
If you just want a ballpark before you measure, this chart gives the weight per foot of common carbon-steel stock at one popular size. Scale linearly: a bar twice as long weighs twice as much, and for any other metal multiply by the density ratio (aluminum ≈ 0.34, stainless ≈ 1.02, copper ≈ 1.14 of steel).
| Steel stock (per foot) | Size | Weight (lb/ft) |
|---|---|---|
| Round bar | 1 in diameter | 2.67 |
| Square bar | 1 in side | 3.40 |
| Hex bar | 1 in across flats | 2.95 |
| Flat bar | 2 in × 1/4 in | 1.70 |
| Round tube | 2 in OD × 1/8 in wall | 2.51 |
| Plate (per sq ft) | 1/4 in thick | 10.21 |
Carbon steel at 0.2836 lb/in³. Figures are computed by this page's calculator; enter your exact size and metal for the precise number.
Steel vs. aluminum: why the same bar weighs a third
Swap steel for aluminum and the weight drops to roughly a third, even though the bar looks identical. The reason is density alone. Aluminum packs 0.0975 lb into each cubic inch; carbon steel packs 0.2836 — about 2.9 times more. Same volume, very different mass.
| 1 in round bar, per foot | Weight (lb/ft) | Weight (kg/ft) |
|---|---|---|
| Aluminum | 0.92 | 0.42 |
| Titanium | 1.53 | 0.70 |
| Carbon steel | 2.67 | 1.21 |
| Stainless steel | 2.72 | 1.24 |
| Brass | 2.89 | 1.31 |
| Copper | 3.05 | 1.38 |
Identical 1 in diameter round bar in six metals, computed by this calculator. The ranking follows density exactly: aluminum is lightest, copper heaviest.
This is why aluminum dominates aircraft, ladders and anything carried by hand, while steel rules where stiffness per dollar matters more than weight. Titanium splits the difference: lighter than steel, far stronger than aluminum, and priced accordingly. Use the weight gap as a first-pass screen, then confirm the strength your design needs.
Why your real weight may differ from the calculator
The math is exact, but real metal carries small variances the formula cannot see. Three account for almost all of the gap between the calculated weight and what the scale reads.
Mill tolerance on dimensions
Stock is rolled and drawn to a tolerance, not a perfect dimension. A "1 inch" bar may measure a few thousandths over or under, and on long runs that adds up. Bar and plate usually run slightly heavy because mills lean to the plus side of tolerance, so calculated weight is a close floor rather than the exact figure.
Alloy and grade differences
The calculator uses one nominal density per metal, but alloys differ. Stainless 304 (about 7,930 kg/m³) is lighter than 316 (about 7,990), and aluminum 6061 differs slightly from pure aluminum. The spread is small — a percent or two — but it matters when you are buying tons or certifying a part.
Coatings, mill scale and finish
Galvanizing, paint and mill scale add weight the bare-metal formula ignores. For most jobs the difference is trivial, but a heavy zinc coat on a large galvanized order is real tonnage. When precision counts, weigh a sample or read the weight off the mill certificate that ships with the metal.
Metal weight definitions
How accurate is this metal weight calculator?
The geometry is exact. Cross-sectional area times length times density is the precise weight of an ideal piece of stock, and the calculator carries full precision before rounding the display. If your dimensions are right and the metal matches, the result is right to a fraction of a percent.
The small remaining gap comes from mill tolerance, the exact alloy grade and any coating — covered above. Treat the result as a precise planning weight: accurate enough to quote freight, size a lift, and order stock, and within a percent or two of the scale for bare metal. For certified or high-precision work, confirm against the mill certificate. Pair it with our rebar and concrete calculators to weigh and quantify a full reinforced pour.
Frequently asked questions about the free Metal Weight calculator
About this metal weight calculator
This metal weight calculator runs entirely in your browser — nothing is sent to a server, and every figure recomputes the instant you change a dimension, shape or metal. It uses the standard area × length × density method with nominal published densities, so the result is the precise weight of ideal stock, accurate enough to quote freight, size a lift and order material.
It's part of our construction calculators collection — sitting alongside the rebar and concrete estimators for the rest of a reinforced pour. Browse every tool on the site from the full calculator directory.