Rebar Calculator - Calculate Rebar Length, Quantity & Weight

How to Use the Rebar Calculator

1. Enter slab dimensions — length and width
2. Set spacing — horizontal and vertical grid spacing
3. Choose rebar size — from #3 (10mm) to #8 (25mm)
4. Get results — number of bars, total length, and weight

Perfect for contractors, engineers, and construction estimators. All calculations happen in your browser.

Features

• Bidirectional grid — calculates both directions
• Multiple rebar sizes — #3 through #8 (metric too)
• Weight estimate — total rebar weight in lbs or kg
• Unit conversion — feet/inches or meters
• Overlap allowance — accounts for lap splices