RebarEstimator: Weight & Lap

RebarEstimator is a practical reinforcement calculator for builders, contractors, estimators, detailers, and DIY project planners. Work out the steel for a concrete slab in seconds, then build a bar bending schedule and send a clean PDF to your crew, supplier, or client.

SLAB ESTIMATE
• Imperial (ft, in, lb) and metric (m, mm, kg). Switch at any time and every number converts automatically.
• Bar counts for both directions of the grid, with separate spacing for each direction and an edge cover setting.
• Single or double (top and bottom) mats.
• Standard sizes #3 to #11 and 6 to 32 mm in one tap, or enter any custom weight per length.
• Total length and weight to order, with a full line-by-line breakdown.
• Waste allowance for bends, cuts, and site loss.

LAP SPLICES AND STOCK BARS
• Lap length as a multiple of bar diameter (30d to 60d), or calculated to ACI 318 (Class A, Class B, compression) or Eurocode 2 from your concrete strength, steel grade, and bar position.
• Bars longer than your stock length are split automatically, with the extra lap material counted in the total.
• Stock bar count worked out by cutting plan: short bars share stock bars and offcuts are reused, so you buy the right number of 10, 20, or 40 ft (6, 9, or 12 m) bars.

COST AND CONCRETE
• Optional cost estimate: enter a price per lb, kg, ton, or tonne, add sales tax, and see the total.
• Optional concrete volume from slab thickness, plus steel per cubic yard or cubic meter as a quick sanity check.

BAR BENDING SCHEDULE
• Straight, L-shape, U-shape, stirrup, ring, and cranked bars.
• Enter outside dimensions, bar size, and quantity. Cut lengths, total length, and weight are worked out for you, with bend deductions and hooks included.
• Totals by bar size and an optional cost estimate.

SHARE AND SAVE
• Export a PDF report of your slab estimate or bending schedule, with your name as the preparer.
• Share a text summary of any estimate.
• Rebar size reference table with diameter, area, weight, and lap length.
• Save, update, and reload named scenarios with notes.

Estimates only. Always verify quantities against your drawings and local building code before ordering. Lap and development lengths are simplified straight-bar values for estimating, not a structural design check.