Reinforcing Steel (C-50) · Lesson 1 of 7

Rebar Weight Takeoff: Bar Sizes, Cover, and Tons

"Rebar Weight Takeoff: Bar Sizes, Cover, and Tons" is lesson 1 of 7 in the Reinforcing Steel (C-50) Learning Hub. It opens with "Reinforcing Steel Is Bought and Sold by Weight" and works through 5 short steps, then a worked example you can check yourself against.

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Steps in this lesson

  1. Reinforcing Steel Is Bought and Sold by Weight
  2. Know the Weight Per Foot for Each Bar Size (Caltrans Section 52-1.04)
  3. Cut Length: Subtract Cover from Both Ends
  4. Count the Bars: Round the Spaces UP
  5. Multiply, Convert to Tons, and Remember Laps Are Paid For

The worked example in the course applies this lesson to a realistic job in 6 steps, from "Find the cut length of each bar" through "All ten footings".

What you'll be able to do

  • Explain the main idea of "Rebar Weight Takeoff: Bar Sizes, Cover, and Tons" in plain language you can use on the exam.
  • Apply this step with confidence: "Cut Length: Subtract Cover from Both Ends".
  • Apply this step with confidence: "Count the Bars: Round the Spaces UP".
  • Apply this step with confidence: "Multiply, Convert to Tons, and Remember Laps Are Paid For".
  • Test yourself on the worked example and the quick-check quiz inside the classroom.
REBAR WEIGHT TAKEOFF: ONE FOOTING MAT2025 Caltrans Std Spec §52-1.04 bar weights | 2025 CRC R403.1.3.5.3 cover8'-0" x 8'-0" footingbar = 96 - 2(3) = 90" = 7.5 ftTHE TAKEOFF - #5 @ 8" O.C. E.W.1Bar length: 96" - 2(3") = 90" = 7.5 ft2Spaces: 90 / 8 = 11.25 round UP to 123Bars each way: 12 + 1 = 134Both ways: 13 x 2 = 26 bars5Length: 26 x 7.5 ft = 195 ft6Weight: 195 ft x 1.043 lb/ft = 203.4 lb7Ten footings: 2,034 lb = 1.02 tonsActual spacing = 90 / 12 = 7.5" (never wider than 8")Bar sizeCaltrans lb/ft#30.376#40.668#51.043#61.502#72.044#82.670RESULT: 26 bars x 7.5 ft = 195 ft = 203.4 lb per footing10 footings = 2,034 lb = 1.02 tons (before laps, hooks and waste)Weight = total length x lb/ft (Caltrans §52-1.04). Straight bars only; laps and hooks are added separately.CC
The diagram for this lesson, exactly as it appears in the Learning Hub.

The first steps of this lesson

Step 1: Reinforcing Steel Is Bought and Sold by Weight

Fabricators price rebar by the pound, hundredweight, or ton (2,000 lb), not by the piece, so every reinforcing steel bid starts with a takeoff: total length of each bar size, converted to weight. The 2025 Caltrans Standard Specifications work the same way: Section 52-1.04 says the payment quantity of bar reinforcing steel is the calculated weight of the bars and wire.

Step 2: Know the Weight Per Foot for Each Bar Size (Caltrans Section 52-1.04)

Section 52-1.04 prints a table titled "Bar Reinforcing Steel Quantities": #3 = 0.376 lb/ft (0.375 in. nominal diameter), #4 = 0.668 (0.500), #5 = 1.043 (0.625), #6 = 1.502 (0.750), #7 = 2.044 (0.875), #8 = 2.670 (1.000), #9 = 3.400 (1.128), #10 = 4.303 (1.270), #11 = 5.313 (1.410), #14 = 7.650 (1.693), #18 = 13.600 (2.257). Its note says the bar number approximates the number of eighths of an inch in the nominal diameter, and that nominal diameter is the diameter of a plain round bar with the same weight per foot. The same section prints a steel density of 0.2833 lb per cubic inch (for wire), which checks the table: #5 area = 0.7854 x 0.625 x 0.625 = 0.3068 sq in; x 12 in. x 0.2833 = 1.043 lb/ft.

The remaining 3 steps, the worked example and the quiz are in the course. This is a preview. The full lesson, with the step-by-step explanations, a worked example and a quick-check quiz, is inside the classroom.

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