TryBuildCalc8mm Steel Weight Calculator(TMT Bar Weight per Meter & Total)
Calculate steel bar weight instantly.
Calculate 8mm steel bar weight for stirrups, ties, and light reinforcement. Adjust diameter, length, quantity, and wastage for your steel takeoff.
🕒 Last updated: August 11, 2026
Weight per Bar (kg)
31.605 kg
0.395 kg/m
Total Weight
31.60 kg
Final Weight
(Including Wastage)
33.19 kg
Includes 5% wastage
(1.58 kg)
Approx. 32 bars per ton (1000 kg)
8mm steel weight
This page is useful for estimating lighter bars commonly used for stirrups and ties.
The calculator is pre-filled for this steel weight use case. Edit any input and the worked example will update from the active values.
- Default diameter: 8 mm.
- Default length: 80 m.
- Includes wastage.
How does this steel weight calculator work?
Understanding how steel weight is calculated helps in verifying estimates and planning reinforcement quantities more effectively.
Steel weight is calculated using a standard formula based on diameter and length of the bar.
Step 1 — Identify Bar Diameter
Select the diameter of the steel bar (e.g., 8 mm, 10 mm, 12 mm, etc.).
Step 2 — Convert Length to Meters
Ensure that the bar length is in meters. If given in feet or inches, convert it to meters.
Step 3 — Apply Steel Weight Formula
Where:
- D — diameter of the bar (in mm)
- Length — length of the bar (in meters)
Step 4 — Calculate Total Steel Weight
Multiply the weight of a single bar by the total number of bars to get the overall steel requirement.
Step 5 — Add Wastage (Optional)
Wastage is optional and depends on site conditions such as cutting, bending, and handling losses.
This formula is widely used in civil engineering standards such as IS codes and international construction practices.
Worked Example
Input Values Used
| Input | Value |
|---|---|
| Bar Diameter | 8 mm |
| Bar Length | 80 m |
| Quantity | 1 bars |
| Wastage | 5% |
Step 1 — Weight per Meter
| Calculation | Substitution | Result |
|---|---|---|
| Weight per meter | 8² ÷ 162 | 0.395 kg/m |
Step 2 — Weight per Bar and Total Weight
| Calculation | Substitution | Result |
|---|---|---|
| Weight per bar | 0.395 × 80 | 31.605 kg |
| Total weight | 31.605 × 1 | 31.60 kg |
Step 3 — Final Weight (with Wastage)
| Calculation | Substitution | Result |
|---|---|---|
| Wastage weight | 31.60 × 5 ÷ 100 | 1.58 kg |
| Final weight | 31.60 + 1.58 | 33.19 kg |
Therefore, for 1 bar of 8mm diameter at 80 m each, you need approximately 33.19 kg of steel (including 5% wastage).
Disclaimer: This calculator provides approximate results for planning and estimation purposes only. Actual requirements may vary based on site conditions, materials, workmanship, and local building regulations. Always consult a qualified engineer, architect, or construction professional before making final decisions.