Rebar Weight Converter

Convert between rebar length, quantity and weight with ease

Conversion Options
Rebar Sizes
mm
Unit System

Convert Length to Weight

Enter the total length of rebar to calculate the total weight

m
mm
Result
Total Weight: 88.78 kg
Formula: Weight = (D²/162) × Length = (12²/162) × 100 = 88.78 kg

Convert Weight to Length

Enter the total weight of rebar to calculate the total length

kg
mm
Result
Total Length: 193.05 m
Formula: Length = (Weight × 162) / D² = (500 × 162) / 16² = 193.05 m

Convert Bars to Weight

Enter the number of bars and their length to calculate the total weight

m
mm
Result
Total Weight: 106.67 kg
Formula: Weight = (D²/162) × Length × Count = (12²/162) × 6 × 20 = 106.67 kg
How It Works

Metric System:

Weight (kg) = (D²/162) × Length (m)
Where D is diameter in mm

Imperial System:

Weight (lb) = (D²/2.67) × Length (ft)
Where D is diameter in inches

The formulas are derived from steel density of 7850 kg/m³ or 490 lb/ft³. If you're working with different materials, you might find our mass and weight converter helpful for cross-referencing densities.

Metric Sizes:

  • #10 (10mm)
  • #12 (12mm)
  • #16 (16mm)
  • #20 (20mm)
  • #25 (25mm)
  • #32 (32mm)

Imperial Sizes:

  • #3 (3/8")
  • #4 (1/2")
  • #5 (5/8")
  • #6 (3/4")
  • #7 (7/8")
  • #8 (1")

Practical Rebar Conversion Guide

What This Rebar Calculator Helps With

This tool solves everyday construction and DIY challenges:

  • Material Estimation: Calculate exactly how much rebar you need for concrete slabs, foundations, or walls. For precise concrete volume, pair this with our concrete volume converter to ensure accurate pour estimates.
  • Budget Planning: Convert length measurements to weight for accurate cost calculations
  • Transport Planning: Determine if your vehicle can handle the weight of rebar you're transporting
  • Project Verification: Check if the delivered rebar matches your order by converting weight back to length
  • Waste Reduction: Precisely calculate needs to minimize leftover materials

When People Use This Conversion

Home & DIY Projects
  • Building a concrete patio or driveway
  • Creating foundation for a shed or garage
  • Reinforcing concrete steps or retaining walls
  • Small concrete countertop projects
Professional Construction
  • Estimating material for large concrete pours
  • Verifying supplier deliveries
  • Planning crane loads and transportation
  • Calculating reinforcement for structural elements

Real-Life Examples & Applications

Example 1: Backyard Concrete Slab
You're pouring a 4×6 meter patio slab using #12 (12mm) rebar on a 0.5m grid. This calculator helps determine you need approximately 168 meters of rebar weighing about 150kg. For more complex layouts, our beam load converter can help with structural calculations.

Example 2: Material Delivery Check
Your supplier delivered 2000kg of #16 rebar. Use the "Weight to Length" tab to verify you received approximately 1,235 meters as ordered. The pipe weight converter offers similar verification for tubular materials.

Example 3: Transport Planning
You need to haul 50 pieces of #20 rebar, each 6 meters long. The calculator shows this weighs about 1,110kg - now you know if your truck can handle it. For overall vehicle load planning, our weight converter tool helps with unit conversions.

Simple Unit Explanations

  • #3, #4, #5 etc.: Rebar size numbers - higher numbers mean thicker bars
  • mm (millimeters): Metric diameter measurement - 12mm is about as thick as your pinky finger. Use our length converter to switch between metric and imperial.
  • inches ("): Imperial diameter - 1/2" (#4) is about the width of a standard pencil
  • kg vs. lb: 1 kg = 2.2 lb. A standard bag of sugar is 1kg. Our mass converter handles all weight unit conversions.
  • m vs. ft: 1 meter = 3.28 feet. Most doorways are about 2 meters tall

Input Usage Guidance

Quick Measurement Tips:
  • Measure rebar length in straight lines - bends add extra length
  • Use the standard size buttons for common projects
  • Check your tape measure units - metric or imperial
  • For multiple bars of different lengths, calculate each separately
  • Remember: rebar is usually sold in standard lengths (6m, 12m, 20ft)

Understanding Your Results

  • Weight Results: Use this to calculate costs (rebar is typically priced per kg or ton)
  • Length Results: Helps visualize how much material you're working with
  • Bending Allowance: Always enable this for bent rebar (stirrups, hooks, corners)
  • Safety Margin: Add 5-10% extra to your final calculation for cutting waste

Everyday Mistakes to Avoid

  • Mixing Units: Don't enter meters with inches - stick to one system. Our length converter helps normalize units before calculation.
  • Ignoring Bends: Bent rebar uses more material - always check the bending allowance
  • Forgetting Overlap: Rebar needs overlap at joints - add 40x diameter extra length
  • Rust Consideration: Heavily rusted rebar weighs slightly less than clean steel
  • Standard Lengths: Suppliers sell specific lengths - round up to nearest available

Mobile Usage Tips

  • Turn phone sideways for better visibility of all options
  • Tap the standard size buttons for quick diameter selection
  • Use your phone's calculator for additional adjustments
  • Take screenshots of your calculations for reference at the supply store
  • Bookmark this page for quick access on job sites

Accessibility Notes

  • All buttons work with keyboard navigation (Tab key)
  • Form fields have clear labels for screen readers
  • High contrast colors for better visibility
  • Tooltips provide additional context without cluttering the interface
  • Simple, consistent layout for easier cognitive processing

Quick Conversion Tips

Rule of Thumb Estimates:
  • #10 (10mm) rebar ≈ 0.62 kg/m
  • #12 (12mm) rebar ≈ 0.89 kg/m
  • #16 (16mm) rebar ≈ 1.58 kg/m
  • #4 (1/2") rebar ≈ 0.668 lb/ft
  • #5 (5/8") rebar ≈ 1.043 lb/ft
  • #6 (3/4") rebar ≈ 1.502 lb/ft

Common FAQs

This calculator uses standard industry formulas and is accurate for planning purposes. Actual weights may vary slightly due to manufacturing tolerances, surface conditions (rust), and exact steel composition. Always add 5-10% safety margin for project planning.

The calculator shows bare steel weight. Galvanized or epoxy-coated rebar weighs slightly more (2-5% depending on coating thickness). For critical applications, consult your supplier for exact coated weights.

Yes, this works for any round steel bars of similar density. However, rebar has ribs that add about 6-8% more surface area. For smooth steel bars, you might get slightly different actual weights. For other metal shapes, check out our pipe weight calculator or rebar tool for specific applications.

Accuracy Disclaimer

Important: This tool provides estimates for planning and educational purposes. While we use industry-standard formulas, actual weights may vary due to:

  • Manufacturing tolerances (±2-3% is common)
  • Surface conditions (rust, mill scale)
  • Exact steel density variations
  • Measurement inaccuracies

For commercial transactions or critical structural calculations, consult professional engineers and use certified scales for verification.

Device Compatibility Notes

  • Fully responsive design works on phones, tablets, and desktops
  • Compatible with all modern browsers (Chrome, Firefox, Safari, Edge)
  • No plugins or downloads required
  • Works offline after initial page load
  • Touch-friendly buttons and inputs

Update Notice

Last Updated: November 2025

This calculator has been reviewed for accuracy and usability. We periodically update content to reflect best practices and user feedback. If you have suggestions, please contact us through our website.

Construction & Engineering Tools

For comprehensive project planning, explore these related calculators: determine concrete requirements with our concrete volume estimator, check beam load capacities for structural integrity, and verify material weights using the pipe weight tool. For general unit conversions across all your construction materials, our weight converter and length converter provide complete unit flexibility.

This practical guide is designed to help you use the rebar calculator effectively for real-world projects. Always follow local building codes and consult professionals for structural engineering decisions.