Concrete & Reinforcement

Rebar Calculator

Enter slab dimensions, bar spacing, cover, stock length, lap, bar size, and waste to prepare a material takeoff.

Open Rebar CalculatorNo signup required · Updates as you type
01Bars in each grid direction
02Installed and order length
03Stock pieces and estimated weight
How it works

From measurements to an order-ready estimate

  1. Enter slab length, width, spacing, and concrete cover.
  2. Choose bar size, stock length, lap allowance, and grid direction.
  3. Review bar counts, installed length, stock pieces, and order weight.
Calculate now
Before you order

Use field measurements and supplier specifications

TerraCalc does not provide structural design. Use spacing, cover, bar size, lap, and layers from approved plans or a qualified design professional.

Common questions

Rebar Calculator questions

Does TerraCalc add waste?

Yes. You control the waste allowance so the estimate can reflect cuts, spill, settlement, compaction, laps, or other project conditions.

Can I use metric measurements?

Yes. TerraCalc supports imperial and metric inputs for its material and reinforcement calculators.

Should I verify the result?

Yes. Recheck site measurements and confirm density, package size, selling increment, product specification, and delivery limits with the supplier or project professional.