Brass weight calculator
Brass weighs about 8.5 kg per cubic decimetre — 8 % more than steel. The calculator handles round bar, sheet, flat bar and tube; hex bar, which it does not cover, has a table of its own. Below are also the densities of the common grades: CuZn37, CuZn39Pb3 and CuZn40.
Short answer
Brass weighs 8.50 kg/m² for every millimetre of sheet thickness (CuZn37: 8.44). A Ø20 round bar weighs 2.67 kg/m, a 17 mm hex bar 2.13 kg/m. That is 8 % more than steel of the same size. Common sizes are in the tables below.
Brass round bar: weight per metre
| Diameter, mm | Cross-section, mm² | kg/m | 3 m bar, kg |
|---|---|---|---|
| 5 | 19.6 | 0.167 | 0.50 |
| 6 | 28.3 | 0.240 | 0.72 |
| 8 | 50.3 | 0.427 | 1.28 |
| 10 | 78.5 | 0.668 | 2.00 |
| 12 | 113.1 | 0.961 | 2.88 |
| 15 | 176.7 | 1.502 | 4.51 |
| 16 | 201.1 | 1.709 | 5.13 |
| 20 | 314.2 | 2.670 | 8.01 |
| 25 | 490.9 | 4.172 | 12.52 |
| 30 | 706.9 | 6.008 | 18.02 |
| 40 | 1 256.6 | 10.681 | 32.04 |
| 50 | 1 963.5 | 16.690 | 50.07 |
Brass hex bar: weight per metre
Brass hex is mostly free-machining CuZn39Pb3 — nuts, fittings and valve bodies are turned from it. The size is given across flats (S).
| Across flats S, mm | Cross-section, mm² | kg/m | 3 m bar, kg |
|---|---|---|---|
| 8 | 55.4 | 0.471 | 1.41 |
| 10 | 86.6 | 0.736 | 2.21 |
| 12 | 124.7 | 1.060 | 3.18 |
| 13 | 146.4 | 1.244 | 3.73 |
| 14 | 169.7 | 1.443 | 4.33 |
| 17 | 250.3 | 2.127 | 6.38 |
| 19 | 312.6 | 2.657 | 7.97 |
| 22 | 419.2 | 3.563 | 10.69 |
| 24 | 498.8 | 4.240 | 12.72 |
| 27 | 631.3 | 5.366 | 16.10 |
| 30 | 779.4 | 6.625 | 19.88 |
| 32 | 886.8 | 7.538 | 22.61 |
| 36 | 1 122.4 | 9.540 | 28.62 |
| 41 | 1 455.8 | 12.374 | 37.12 |
A hex bar is 10.3 % heavier than a round bar whose diameter equals S, because its corners stand proud of the inscribed circle. So enter round bar Ø = S in the calculator and multiply by 1.103: for a 17 mm hex, 1.929 × 1.103 = 2.13 kg/m.
Brass sheet: weight per square metre and per sheet
| Thickness, mm | kg/m² | 1000×2000 sheet, kg | 1250×2500 sheet, kg | m² per 100 kg |
|---|---|---|---|---|
| 0.5 | 4.25 | 8.5 | 13.3 | 23.53 |
| 0.8 | 6.80 | 13.6 | 21.3 | 14.71 |
| 1 | 8.50 | 17.0 | 26.6 | 11.76 |
| 1.5 | 12.75 | 25.5 | 39.8 | 7.84 |
| 2 | 17.00 | 34.0 | 53.1 | 5.88 |
| 3 | 25.50 | 51.0 | 79.7 | 3.92 |
| 4 | 34.00 | 68.0 | 106.3 | 2.94 |
| 5 | 42.50 | 85.0 | 132.8 | 2.35 |
| 6 | 51.00 | 102.0 | 159.4 | 1.96 |
| 8 | 68.00 | 136.0 | 212.5 | 1.47 |
| 10 | 85.00 | 170.0 | 265.6 | 1.18 |
Brass sheet and strip are usually CuZn37 (8.44 g/cm³): a 1000×2000×1 sheet weighs 16.9 kg in it instead of the 17.0 kg in the table. That difference changes neither the quote nor the haulage.
Brass tube: weight per metre
| Tube D×s, mm | Bore, mm | kg/m | 5 m length, kg |
|---|---|---|---|
| 8×1 | 6 | 0.187 | 0.93 |
| 10×1 | 8 | 0.240 | 1.20 |
| 12×1 | 10 | 0.294 | 1.47 |
| 15×1 | 13 | 0.374 | 1.87 |
| 16×1 | 14 | 0.401 | 2.00 |
| 20×1 | 18 | 0.507 | 2.54 |
| 22×1 | 20 | 0.561 | 2.80 |
| 25×1.5 | 22 | 0.941 | 4.71 |
| 30×1.5 | 27 | 1.142 | 5.71 |
| 40×2 | 36 | 2.029 | 10.15 |
Brass grades and density
| Grade | EN number | Typical use | ρ, g/cm³ | 1000×2000×1 sheet, kg | vs calculator, % |
|---|---|---|---|---|---|
| CuZn37 | CW508L | sheet and strip, deep drawing, bending | 8.44 | 16.88 | −0.7 |
| CuZn39Pb3 | CW614N | free-machining round and hex bar | 8.47 | 16.94 | −0.4 |
| CuZn40 | CW509L | plate and hot forgings | 8.40 | 16.80 | −1.2 |
Brass gets lighter as the zinc content goes up, and the lead in free-machining grades pulls it back up slightly — hence 8.40 for CuZn40 and 8.47 for CuZn39Pb3. For ordering and transport the calculator figure is enough. Zinc and lead matter for welding: zinc boils at about 907 °C, close to the melting point of brass itself, so it fumes off the weld pool — brass is more often brazed, and zinc fume needs extraction (see welding fumes).
How to work out brass weight yourself
- Cross-section in mm²: round bar — π·d²/4, hex — 0.866·S², sheet and flat — a·b, tube — π·t·(D−t).
- Mass per metre in kg/m: area × 8.50 / 1000 (or the grade density from the table).
- Mass of a piece: kg/m × length in metres.
The same sizes in copper are in the copper weight calculator, in steel in the metal weight calculator, and in aluminium on the aluminium round bar page. All the tools are in the calculators section.
Frequently asked questions
What is the density of brass?
8.40–8.47 g/cm³ depending on the grade: CuZn40 8.40, CuZn37 8.44, free-machining CuZn39Pb3 8.47. The calculator uses 8.50, so its result is 0.4–1.2 % high — inside the dimensional tolerance of bar and sheet. The product standards EN 12163/12164 give a rounded “about 8.4” for these grades.
How much does a 20 mm brass bar weigh?
2.67 kg/m at 8.50 g/cm³, so a 3 m bar is 8.0 kg. In CuZn39Pb3 (8.47) it comes to 2.66 kg/m.
How do I work out the weight of brass hex bar?
The area of a hexagon is 0.866·S², where S is the size across flats. A 17 mm hex has 250.3 mm² and weighs 2.13 kg/m. The shortcut: round bar of diameter S × 1.103 — which is also how to get it out of the calculator, which has no hex option.
Which is heavier, brass or copper?
Copper, by about 5 % (8.96 against 8.50 g/cm³). Brass is 8 % heavier than steel and more than three times heavier than aluminium.
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