BuildMeter guide · Concrete & Masonry
Rebar Size and Weight Chart
Compare common U.S. reinforcing-bar designations, nominal diameters, cross-sectional areas and approximate weight per foot, then use verified project schedules for ordering.
Direct answer
What to know first
Rebar size numbers identify standardized bar dimensions, while total weight equals bar length multiplied by weight per unit length. Use the project bar schedule and a recognized reference for the exact size, grade, length, bends and quantity; a weight chart supports takeoff but does not design reinforcement.
Open Rebar Weight CalculatorCommon U.S. rebar sizes and approximate weight
Reinforcing-bar takeoffs usually begin with the bar designation shown on the structural drawings. The number identifies a standardized nominal size; it is not a field-measured diameter rounded to the nearest fraction. Weight is then estimated from the published mass per unit length and the total scheduled bar length.
| Bar size | Nominal diameter | Nominal area | Approx. weight |
|---|---|---|---|
| #3 | 0.375 in. | 0.11 in² | 0.376 lb/ft |
| #4 | 0.500 in. | 0.20 in² | 0.668 lb/ft |
| #5 | 0.625 in. | 0.31 in² | 1.043 lb/ft |
| #6 | 0.750 in. | 0.44 in² | 1.502 lb/ft |
| #7 | 0.875 in. | 0.60 in² | 2.044 lb/ft |
| #8 | 1.000 in. | 0.79 in² | 2.670 lb/ft |
| #9 | 1.128 in. | 1.00 in² | 3.400 lb/ft |
| #10 | 1.270 in. | 1.27 in² | 4.303 lb/ft |
| #11 | 1.410 in. | 1.56 in² | 5.313 lb/ft |
Use this table as a takeoff reference only. The project schedule controls bar size, grade, coating, bends, lap details and placement. Larger bar sizes and metric designations are available in recognized reinforcing-steel references.
How to calculate total rebar weight
For straight bars of one size, multiply the total scheduled length by the published weight per unit length:
Total weight = number of bars × cut length × weight per foot
For mixed sizes, calculate each bar group separately and add the weights. Bent bars can often be estimated from their scheduled cut length, but the fabrication list is more reliable than measuring one visible leg at a time.
Worked example
A slab schedule calls for 42 pieces of #4 bar, each cut to 18 ft. Total length is 42 × 18 = 756 ft. Using 0.668 lb/ft, the estimated steel weight is:
756 × 0.668 = 505 lb, approximately.
If a second group contains 20 pieces of #5 bar at 10 ft each, that group adds 200 × 1.043 = about 209 lb. The combined planning weight is about 714 lb before any separately scheduled chairs, dowels or additional bars.
What a bar list should contain
| Item | Why it matters |
|---|---|
| Bar mark | Connects the takeoff to the drawing and bending schedule. |
| Bar size and grade | Controls dimensions, weight and material properties. |
| Quantity | Should be counted by location or bar mark, not guessed from total area. |
| Cut length | Includes bends and extensions shown in the schedule. |
| Shape code or bend dimensions | Prevents straight-length assumptions on fabricated bars. |
| Coating or material type | Epoxy-coated, galvanized, stainless and other bars are not interchangeable. |
Common mistakes
- Using bar diameter as though it were the spacing.
- Multiplying slab area directly by a universal steel rate.
- Forgetting bars in both directions, multiple mats, dowels or edge details.
- Using clear span instead of scheduled cut length.
- Mixing bar weights from different unit systems.
- Adding an arbitrary lap length without reading the project details.
Use the calculators
Use the Rebar Weight Calculator when size, quantity and length are known. Use the Rebar Calculator for a simple grid quantity estimate after spacing and cover have been confirmed.
Sources and professional limits
The Concrete Reinforcing Steel Institute provides bar-identification and ready-reference resources covering standard sizes, diameters, areas and weights. Reinforcement design, lap length, cover, development, grade and placement must come from the project documents and qualified design.