Material weight calculator.
The weight and material cost of round, hex, square, tube, and sheet stock in forty metals and plastics.
Pick a shape and a material
Volume, then density
Every shape here comes down to volume times density. The one number worth memorizing is for the hexagon: 0.866025 is the sine of 60 degrees, and it is what turns an across flats dimension into an area.
Rectangular bar or plate = width × thickness × length
Round tube = π ÷ 4 × (OD² − ID²) × length
Hex bar = 0.866025 × across flats² × length
Square bar = side² × length
Sheet = width × length × thickness
weight in pounds = volume in cubic inches × density in lb/in³
lb/in³ = g/cm³ × 0.0361273
Density of 38 metals and plastics
| Material | Group | g/cm³ | lb/in³ | lb/ft³ |
|---|---|---|---|---|
| Aluminum 6061-T6 | Aluminum | 2.70 | 0.0975 | 168.6 |
| Aluminum 7075-T6 | Aluminum | 2.81 | 0.1015 | 175.4 |
| Aluminum 2024-T3 | Aluminum | 2.78 | 0.1004 | 173.5 |
| Aluminum 5052-H32 | Aluminum | 2.68 | 0.0968 | 167.3 |
| Aluminum A356 cast | Aluminum | 2.68 | 0.0968 | 167.3 |
| Steel 1018 (mild) | Steel | 7.87 | 0.2843 | 491.3 |
| Steel 1045 (medium carbon) | Steel | 7.85 | 0.2836 | 490.1 |
| Steel 12L14 (free machining) | Steel | 7.87 | 0.2843 | 491.3 |
| Steel 4140 (alloy) | Steel | 7.85 | 0.2836 | 490.1 |
| Tool steel A2 | Steel | 7.86 | 0.2840 | 490.7 |
| Tool steel D2 | Steel | 7.70 | 0.2782 | 480.7 |
| Gray cast iron | Steel | 7.20 | 0.2601 | 449.5 |
| Ductile iron | Steel | 7.10 | 0.2565 | 443.2 |
| Stainless 303 | Stainless | 7.90 | 0.2854 | 493.2 |
| Stainless 304 | Stainless | 8.00 | 0.2890 | 499.4 |
| Stainless 316 | Stainless | 8.00 | 0.2890 | 499.4 |
| Stainless 410 | Stainless | 7.80 | 0.2818 | 486.9 |
| Stainless 17-4 PH | Stainless | 7.80 | 0.2818 | 486.9 |
| Brass C360 | Copper alloys | 8.49 | 0.3067 | 530.0 |
| Copper C110 | Copper alloys | 8.94 | 0.3230 | 558.1 |
| Bearing bronze C932 | Copper alloys | 8.93 | 0.3226 | 557.5 |
| Titanium Ti-6Al-4V | Superalloys | 4.43 | 0.1600 | 276.6 |
| Titanium CP grade 2 | Superalloys | 4.51 | 0.1629 | 281.6 |
| Inconel 718 | Superalloys | 8.19 | 0.2959 | 511.3 |
| Inconel 625 | Superalloys | 8.44 | 0.3049 | 526.9 |
| Monel 400 | Superalloys | 8.80 | 0.3179 | 549.4 |
| Magnesium AZ31 | Other metals | 1.77 | 0.0639 | 110.5 |
| Zinc ZAMAK 3 | Other metals | 6.60 | 0.2384 | 412.0 |
| Lead | Other metals | 11.34 | 0.4097 | 707.9 |
| Nickel 200 | Other metals | 8.89 | 0.3212 | 555.0 |
| Acetal (Delrin) | Plastics | 1.41 | 0.0509 | 88.0 |
| Nylon 6/6 | Plastics | 1.14 | 0.0412 | 71.2 |
| UHMW polyethylene | Plastics | 0.94 | 0.0340 | 58.7 |
| PTFE | Plastics | 2.17 | 0.0784 | 135.5 |
| Polycarbonate | Plastics | 1.20 | 0.0434 | 74.9 |
| PEEK | Plastics | 1.32 | 0.0477 | 82.4 |
| ABS | Plastics | 1.04 | 0.0376 | 64.9 |
| G10 / FR4 laminate | Plastics | 1.85 | 0.0668 | 115.5 |
Questions estimators ask about material weight
How do you calculate the weight of a metal bar?
Work out the volume from the shape, then multiply by the density of the material. For a round bar, the volume is pi over four times the diameter squared times the length, in cubic inches. Multiply that by the density in pounds per cubic inch, and the answer is in pounds. A one inch diameter bar of 6061 aluminum, one foot long, is 9.4248 cubic inches at 0.0975 pounds per cubic inch, which is 0.919 pounds.
What is the density of aluminum in pounds per cubic inch?
Aluminum 6061 is 2.70 grams per cubic centimeter, which is 0.0975 pounds per cubic inch. The conversion factor is 0.0361273 pounds per cubic inch for each gram per cubic centimeter. Other common values are 0.2843 for mild steel, 0.2890 for 304 stainless, 0.3067 for C360 brass and 0.1600 for Ti-6Al-4V.
How do you calculate the weight of hex bar?
The cross sectional area of a regular hexagon is 0.866025 times the across flats dimension squared. Multiply that by the length for volume, then by the density for weight. Hex stock is sold and drawn by its across flats dimension, so that is the figure the formula uses.
Does this account for the material I machine away?
No, and that is deliberate. The calculator gives the weight of the stock you buy, which is what you pay for. What ends up in the part is a separate number, and the difference is your chip volume. For quoting, the stock weight is usually the figure that matters, because the scrap value of the chips is a fraction of what the bar cost.
How accurate are these densities?
They are nominal room temperature values, accurate enough for estimating. They vary slightly with temper, with supplier, and with the exact composition inside the specification band, usually by well under one percent, which does not matter for stock weight and material cost. If weight is a controlled characteristic on a drawing, weigh the part.
Should I add a cutoff allowance?
For quoting, yes. The length you buy is longer than the length you use, by the parting tool width, the facing stock, and whatever the bar puller or the chuck cannot reach. On a short run, that remnant can be a significant fraction of the bar. Add it to the length before you calculate, because the allowance is fixed per part and does not scale with part length the way a percentage would.
Who made it, and what it does not do
This tool was written by Shopfloor Agency's lead engineer, who holds a bachelor’s degree in mechanical engineering and builds websites for US manufacturers. It runs entirely in your browser.
The geometry is exact. The densities are nominal values that vary slightly with temper, supplier, and position inside the specification band. That does not matter for estimating, and it does matter for a controlled weight characteristic. The calculator does not add a cutoff allowance, mill tolerance on the stock dimension, or the difference between what you buy and what stays in the part.
If you spot an error, tell us, and we will correct the page and note the change.
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