Apply for financingRebar calculator
This rebar calculator counts a two-way grid: bars each way, the linear feet, and the weight from standard pounds per foot. It does not design the slab or add laps and hooks.
Rebar weight
452lb
A straight grid count for planning. It does not cover laps, hooks, chairs, or a structural design.
How it works
Bars that run the length of the slab are spaced across the width. The count is the width in inches divided by the spacing, rounded down, plus one so the last bar lands on the far edge. Bars that run the width are spaced across the length the same way. Linear feet are count times the bar length. Weight uses nominal ASTM A615 figures: #3 is 0.376 lb/ft, #4 is 0.668, #5 is 1.043, and #6 is 1.502. Those weights are for the bar size, not for epoxy or a mill tolerance you were quoted.
Formula
Linear feet = (bars along the length × slab length) + (bars along the width × slab width). Pounds = linear feet × pounds per foot. No waste factor is applied. Add laps yourself if the stock length is shorter than the slab.
Example
Seventeen bars run the 20-foot direction and fourteen run the 24-foot direction. That is 676 linear feet. At 0.668 pounds per foot the grid is about 452 pounds, before laps, hooks, or chairs.
Tips
If you buy 20-foot sticks for a 24-foot run, you need a lap the design specifies. This count assumes each bar is one piece the full span. Chairs and tie wire are not included.
Equipment
The concrete calculator estimates the yards for the same slab. A mixer or a skid steer for the pour is equipment Dengaro can take an application for, from $15,000 to $2 million. Steel weight is not the financed amount.
Important questions
#3, #4, #5, and #6, at their nominal pounds per foot. Other sizes are not listed. Multiply linear feet by a published weight if you need a different bar.
Yes. The first and last bars sit on the edges, and the bars between them are placed at the spacing you enter, counted with the floor-divide-plus-one method.
The headline rounds to the nearest pound for a planning total. The pounds-per-foot figure on the result is the unrounded nominal weight.
No. Spacing, cover, bar size, and laps come from the design for that slab. This page only counts a regular grid from the spacing you choose.
Financing built into the sale