Rebar Weight Calculator
Enter size, length, and bar count to get total length, net weight, order weight with waste, and ton conversion — based on KS D 3504 unit weight.
Materials needed
In tons (t): 0.62 t
- Total length
- 600 m
- Net weight
- 597 kg
- Unit weight (kg/m)
- 0.995
Based on KS D 3504 deformed rebar unit weight. Order weight adds the waste margin to net weight — confirm extra allowance for splicing and cutting loss before ordering.
What this tool does
The rebar weight calculator instantly computes total length, net weight, order weight (with waste margin), and the ton (t) conversion from just the rebar size (D10-D32), length per bar, and bar count. In reinforced concrete work, bars of the same length can weigh very differently depending on their size — the KS D 3504 (steel bars for concrete reinforcement) standard defines deformed rebar unit weights that scale from 0.560kg/m at D10 up to 6.230kg/m at D32. This calculator multiplies length per bar by bar count to get total length, multiplies that by the size's unit weight to get the net material weight, then adds a waste margin (default 3%) to cover splicing, cutting, and handling losses to arrive at the actual weight you should order. Results are shown in both kilograms and tons, since rebar is commonly priced and traded by the ton, so you can use the figures directly when requesting quotes from rebar suppliers or ready-mix contractors or preparing a material take-off. On sites where footings, columns, and beams each use different bar sizes, running the calculation once per size and summing the results quickly gives an accurate total rebar quantity.
Who uses this
- Estimate weight/quantity by size before placing rebar in footings, columns, and beams
- Calculate total weight and tonnage for a rebar order sheet
- Pre-calculate before requesting quotes from rebar suppliers or ready-mix contractors
- Check the waste-margin quantity to cover splicing and cutting loss
- Compare rebar weight across sizes (D10-D32)
How to use
- 1Select the rebar size (D10-D32) — based on KS D 3504 deformed rebar designations.
- 2Enter the length per bar (m) and the number of bars needed (EA).
- 3Check the waste margin (default 3%) to instantly see total length, net weight, order weight, and the ton conversion.
Weight & ton conversion formula
Total length (m) = length per bar (m) × bar count Net weight (kg) = total length × unit weight (kg/m) Order weight (kg) = net weight × (1 + waste rate) Tons (t) = order weight / 1000 Unit weight (kg/m, KS D 3504 deformed rebar nominal size): D10 0.560, D13 0.995, D16 1.560, D19 2.250, D22 3.040, D25 3.980, D29 5.040, D32 6.230
Real examples
Example 1: D13 rebar, 6m × 100 bars
Total length 600m, net weight 597kg. +3% waste → order weight 614.9kg (0.615t).
Example 2: D25 rebar, 8m × 50 bars
Total length 400m, net weight 1,592kg. +3% waste → order weight 1,639.8kg (1.64t).
Frequently asked questions
What do the numbers in D10, D13, etc. mean?
The number after the D indicates the nominal diameter (mm) of the deformed bar. D13 is roughly 13mm in diameter — larger numbers mean thicker, heavier bars. KS D 3504 defines standard sizes and unit weights from D10 through D32.
Why apply a 3% waste margin?
Rebar loses some material to lap splicing, cutting, and handling. Ordering only the net weight can leave you short on site, so it's standard practice to add a default 3% (more for structures with heavy splicing).
What's the difference between net weight and order weight?
Net weight is the pure rebar weight that actually goes into the structure; order weight adds the waste margin on top so it reflects what you actually need to order. Quotes and order sheets should be based on order weight to avoid shortfalls.
Why is the result shown in tons too?
Rebar is typically priced by the ton in the supply chain. The tool divides the kilogram result by 1,000 to give a ton figure you can use directly for quote comparisons and order sheets.
Does this include splice length or embedment (development) length?
No. This is a simple quantity tool based on the bar length you enter — structural values like lap splice length or embedment length should be added to the length per bar separately before entering it.
Cautions
- •Unit weights are KS D 3504 nominal-size baseline values — actual product weight can vary slightly by manufacturer and rolling tolerance.
- •The 3% waste rate is a default; raise it to 5%+ for structures with heavy splicing or cutting loss.
- •Length per bar does not include splice or embedment length — add those per your structural drawings before entering.
- •When ordering at a per-ton price, quote against the order weight (with waste included) to avoid coming up short.
- •Confirm final sizing against structural drawings and your site supervisor before ordering.
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Last reviewed: 2026-07-16