Rebar Size and Weight Chart
Rebar is sized by number: the number is the diameter in eighths of an inch. These tables give the weight per foot and the quantity of bar for common slab grids.
Bar sizes and weights
| Bar | Diameter (in) | Weight (lb/ft) | kg/m | 20 ft stick (lb) | ft per 100 lb |
|---|---|---|---|---|---|
| #3 | 0.375 | 0.376 | 0.560 | 7.5 | 266 |
| #4 | 0.500 | 0.668 | 0.994 | 13.4 | 150 |
| #5 | 0.625 | 1.043 | 1.552 | 20.9 | 96 |
| #6 | 0.750 | 1.502 | 2.235 | 30.0 | 67 |
Total bar length for slab grids
| Slab (ft) | 12 in | 16 in | 18 in | 24 in |
|---|---|---|---|---|
| 10 × 10 | 20 | 20 | 20 | 20 |
| 12 × 12 | 48 | 24 | 24 | 24 |
| 12 × 16 | 56 | 40 | 28 | 28 |
| 20 × 20 | 80 | 80 | 80 | 40 |
| 24 × 24 | 144 | 96 | 96 | 96 |
The count along each span is floor(span ÷ spacing) + 1. Add 10% for laps and cuts and divide by 20 ft to get the number of sticks. The rebar calculator does this and adds the weight.
Weight of the grid in #3 bars
| Slab (ft) | 12 in | 16 in | 18 in | 24 in |
|---|---|---|---|---|
| 10 × 10 | 8 | 8 | 8 | 8 |
| 12 × 12 | 18 | 9 | 9 | 9 |
| 12 × 16 | 21 | 15 | 11 | 11 |
| 20 × 20 | 30 | 30 | 30 | 15 |
| 24 × 24 | 54 | 36 | 36 | 36 |
Multiply the #3 weights by 1.78 for #4 bars, 2.77 for #5 bars and 4.0 for #6 bars.
Notes on use
- The tables are quantities, not designs. Bar size and spacing come from your plans or an engineer.
- Laps, cover, chairs and tie wire are not included.
- In a slab on grade the steel normally sits in the middle or upper third on chairs.
- See the rebar guide for typical grids.
Frequently asked questions
How much does #4 rebar weigh?
0.668 lb per foot.
What does the rebar number mean?
The diameter in eighths of an inch. #4 is 4/8 in, which is 1/2 in.
How long is a stick of rebar?
Typically 20 ft.
How much rebar for a 20 × 20 slab at 16 in?
80 ft of bar net, plus laps.
How many sticks of #3 in 100 lb?
About 266 ft, or 13 sticks.
Does the table include laps?
No. Add about 10%.
Sources
Estimate only. Results depend on the numbers you enter, ground conditions and your supplier. For structural work consult a licensed engineer and follow local codes. Brand names such as Quikrete and Sakrete are used only to cite published product data. This site is not affiliated with any brand.