#4 Rebar
The bar everyone outside the industry has held: driveways, residential footings and garage slabs run on #4.
1/2 inch diameter, 0.20 in2, 0.668 lb per foot
| Nominal diameter | 1/2 in (12.7 mm) |
| Cross section area | 0.20 in2 (129 mm2) |
| Weight | 0.668 lb per foot (0.994 kg per meter) |
| Typical grade | Grade 60, 60 ksi yield |
| Soft metric name | No. 13 |
| 20 ft stock bar | about 13.4 lb |
| Nearest Canadian bar | 10M, with 15M above it |
Notes for design and site
Half inch bar at 18 or 24 inch centres is the default reinforcing of North American residential concrete: slabs on grade, footings, short retaining walls. It is stiff enough to hold its chair height under foot traffic yet light enough to cut and bend with hand tools, which is why it owns the light construction market.
A 40 diameter rough lap is 20 inches, a number worth memorizing because half the laps in residential work are eyeballed short. Metric drawings call it No. 13.
Related Calculators and Reference
- Rebar Weight and Spacing Calculator: runs to pounds for the lumber yard order.
- Slab on Grade Takeoff Calculator: the slab this bar usually sits in.
- Quantity Takeoff Calculator: concrete, rebar and formwork together.
- #5 Rebar: the structural workhorse one step up.
- Grade 60 Rebar: the strength values behind the bar.
- Concrete Reinforcing Steel Institute: the US industry body for reinforcing steel.