Rebar weight & BBS calculator.
Build a bar bending schedule in the browser. Add a row per bar mark and get the weight per diameter and the total tonnage as you type. Free, no sign-up, and nothing leaves your browser.
| Bar mark | Dia | Cut length | No. | kg/m | Weight | |
|---|---|---|---|---|---|---|
| 0.888 | 462.4 | |||||
| 0.617 | 284.1 | |||||
| 2.466 | 219.0 |
Summary by diameter
- 10 mm284.1 kg
- 12 mm462.4 kg
- 20 mm219.0 kg
Total steel
965.47 kg
192 bars · 1,070.4 m
Unit weight table.
Kilograms per metre for IS 1786 bar sizes, computed from a steel density of 7,850 kg/m³.
| Diameter | Weight (kg/m) | Weight per 12 m bar | Bars per tonne (12 m) |
|---|---|---|---|
| 6 mm | 0.222 | 2.66 kg | 375 |
| 8 mm | 0.395 | 4.74 kg | 211 |
| 10 mm | 0.617 | 7.40 kg | 135 |
| 12 mm | 0.888 | 10.65 kg | 93 |
| 16 mm | 1.578 | 18.94 kg | 52 |
| 20 mm | 2.466 | 29.59 kg | 33 |
| 25 mm | 3.853 | 46.24 kg | 21 |
| 28 mm | 4.834 | 58.00 kg | 17 |
| 32 mm | 6.313 | 75.76 kg | 13 |
| 36 mm | 7.990 | 95.88 kg | 10 |
| 40 mm | 9.865 | 118.38 kg | 8 |
About this calculator.
What is the formula for the unit weight of a steel bar?
Weight per metre equals d² divided by 162, where d is the bar diameter in millimetres. It comes from multiplying the cross-sectional area (πd²/4) by the density of steel, 7,850 kg/m³. The exact divisor is 162.196; 162 is the rounded shorthand used on site. This calculator uses the exact value.
How do I calculate the total weight of reinforcement?
Multiply the unit weight by the cut length of one bar and then by the number of bars, and sum across every bar mark. Add a row per bar mark above and the running total updates as you type.
Does this calculate cutting length with bend deductions?
Not yet — enter the cut length you have already worked out. Cutting length depends on shape code, bend angle and mandrel radius under the governing code. The BS 8666 shape codes and their formulas are set out on our BBS service page.
Is the calculator free, and is my data stored?
Free, no sign-up, and nothing is stored. The calculation runs entirely in your browser and no schedule data is ever sent to us. The share button encodes your rows into the page URL so you can send it to a colleague — that link never touches our server either.
Which bar sizes does it cover?
IS 1786 sizes from 6 to 40 mm for Indian projects, BS 4449 from 6 to 50 mm for UK and Gulf work, and ASTM A615 #3 to #18 for US-standard projects.
Want the real schedule?
We prepare full bar bending schedules with shape codes, cutting lengths and bend deductions applied — checked by a second engineer before issue.