Work out rebar quantity instantly with clear inputs, formula shown and shareable results.
For a two-way mat the number of bars in each direction is the clear span perpendicular to them divided by the spacing, plus one because both edge bars are counted. Bar length is the slab dimension less cover at each end, and the totals give the running metres to convert into weight.
Bar count
Bars = floor(clear width / spacing) + 1, taken in each direction
Running length
Total m = bars each way x their respective clear span
Bars = floor(clear width / spacing) + 1, taken in each direction. For a two-way mat the number of bars in each direction is the clear span perpendicular to them divided by the spacing, plus one because both edge bars are counted.
No. Add lap lengths where bars are spliced and hook or crank allowances from the bar bending schedule; those can add 5-10 percent to the running metres.
This calculator takes 4 inputs: Slab length, Slab width, Bar spacing both ways, Side cover. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.