Rebar Weight Calculator
Compute rebar weight from bar diameter and length. Unit weight follows <code>W = 0.006165 × d²</code> kg/m (d in mm), with metric and imperial output. A unit-weight table for the common sizes is listed below.
Disclaimer：Results are produced by deterministic formulas and are intended for quantity estimating and option comparison only. A qualified engineer must verify them against the project specification, design documents and actual site conditions before use. The author accepts no liability for any loss arising from their use.
ASSUMPTIONS
RESULT
CALCULATION
Theoretical weight of common rebar sizes (Ø6 – Ø40 mm)
| Bar size | Section area mm² | Theoretical weight kg/m | Weight lb/ft |
|---|---|---|---|
| Ø6 mm | 28.3 | 0.222 | 0.149 |
| Ø8 mm | 50.3 | 0.395 | 0.265 |
| Ø10 mm | 78.5 | 0.617 | 0.414 |
| Ø12 mm | 113.1 | 0.888 | 0.597 |
| Ø14 mm | 153.9 | 1.208 | 0.812 |
| Ø16 mm | 201.1 | 1.578 | 1.061 |
| Ø18 mm | 254.5 | 1.997 | 1.342 |
| Ø20 mm | 314.2 | 2.466 | 1.657 |
| Ø22 mm | 380.1 | 2.984 | 2.005 |
| Ø25 mm | 490.9 | 3.853 | 2.589 |
| Ø28 mm | 615.8 | 4.833 | 3.248 |
| Ø32 mm | 804.2 | 6.313 | 4.242 |
| Ø36 mm | 1017.9 | 7.990 | 5.369 |
| Ø40 mm | 1256.6 | 9.864 | 6.628 |
METHOD
Unit weight
W = 0.006165 × d² kg/m (d in mm); total weight Wtotal = W × L × n.- The unit-weight formula derives from a steel density of 7850 kg/m³:
W = π/4 × (d/1000)² × 7850 ≈ 0.006165 d²(d in mm). - Actual bar weight is affected by rolling tolerances; for bulk settlement use weighed weights or the mill-certified nominal weight.
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