Rebar Calculator (Weight, Length & Spacing)

Expert Guide

The definitive tool for basic rebar estimation. Calculate weight, running length, or the number of bars needed for any span.

Steel rods and rebar being tied by worker on construction site

⚡ Quick Answer

Order steel by total weight in kg/tonnes. For a 12mm bar over 5m at 150mm spacing: 35 bars × (12²/162.2) × 5 = 373 kg. For professional steel procurement with competitive rates, visit pro.nirmansutra.com.

🛠️ How It Works

Metric: Weight (kg) = (Diameter² / 162.2) × Total Length. Imperial: Weight (lbs) = Unit Weight (lb/ft) × Total Length (ft).

Choose whether you want to find the weight, total length, or the number of bars needed.
For weights, select the bar diameter (using standard D²/162.2 density).
For spacing, enter the total span and your engineer-specified spacing (typically 100mm-200mm).
The tool provides precise tonnage and piece counts for site procurement.

📐 Calculation Formula

Weight = (D² / 162.2) × Length × Qty

Bars = (Net Span / Spacing) + 1

📋 Real-Life Example

Example: Weight of 20 bars of 16mm TMT, each 6m long.
1. Unit Weight = 16² / 162.2 = 1.578 kg/m.
2. Weight per bar = 1.578 × 6 = 9.47 kg.
3. Total Weight = 9.47 × 20 = 189.4 kg.
4. In Tonnes = 0.189 T.

❓ Frequently Asked Questions

How do I calculate the weight of a rebar?

The standard formula is D²/162.2 (metric, kg/m). For more rebar reference charts, see our [Engineering Blog](https://blog.nirmansutra.com/).

What is the weight of one 12mm rebar?

A standard 12mm TMT bar weighs 0.888 kg per meter. A full 12m bar weighs about 10.65 kg.

Does this calculator include wastage?

This tool calculates net weight. Add 3-5% for cutting wastage and 2% for bend deductions on site.

Where can I get current steel rates in Nepal?

Visit [pro.nirmansutra.com](https://pro.nirmansutra.com/) for verified supplier rates and bulk procurement assistance.