Reinforcement grid

Rebar Calculator

Estimate rebar length and pieces for a simple slab grid.

US units 10% default waste Bag and yard estimates

Rebar estimate

Grid dimensions

Estimates are for planning and ordering only.
Bag counts are rounded up to whole bags.
Ready-mix yards are rounded up to the nearest 0.25 cubic yard.
Default waste is 10%. Increase it for uneven excavation, spillage, or complex forms.
Verify structural work with a contractor, engineer, or supplier before pouring.

This calculator estimates a simple two-direction grid with equal spacing and edge clearance.

It does not design reinforcement. Structural requirements depend on load, soil, slab use, code and engineering details.

Concrete mix Rebar Tube forms Mixing tools Trowels and floats

How is rebar spacing calculated?

The clear slab dimension is divided by spacing, then one bar is added so both sides are covered.

Does this include lap splices?

No. Add extra material if your layout requires overlaps or splices.

Can this design a structural slab?

No. It is a quantity estimator, not an engineering design.