How to use the Rebar Calculator

Estimate the number of rebar grid runs and total linear feet in a rectangular slab.

Calculation formula

Count of bars parallel to length = ceil(width × 12/spacing) + 1; parallel to width = ceil(length × 12/spacing) + 1; total linear feet = sum of runs × (1 + waste%).

Recommended steps

1. Enter values using the units shown beside each field.
2. Review whether the example assumptions match your situation.
3. Run the calculator and compare the key metrics.
4. Use the source data or official rates when precision matters.

Known limitations

Does not check structural design, bar size, required lap development length, support chairs, covers or codes.