Aisha K.
Mar 12, 2026
Clean layout and the results update instantly. Exactly what I needed for a quick planning check.
Masonry & Concrete
Rebar Weight Calculator by Length & Spacing
Pieces = length ÷ spacing + 1; weight = pieces × length × lb/ft.
Rebar pieces and weight for a slab or footing run. Planning estimates only — verify measurements and local codes on site.
Inputs
5500
624
0.22
Smart analysis
Recommendations
Tailored to your live inputs and result—guidance only, not professional advice.
- Interpret
Treat this as a planning estimate
Primary result: Rebar weight = 1,095.5 lbs. Re-run with optimistic and pessimistic inputs to understand the range—not just a single point.
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Plain-English guide
Terms & how it works
Confused by a field? Read the short definitions here while you use the tool.
Run length (ft)
The “Run length (ft)” value used in this tool’s formula. Adjust it to see results update live.
Spacing (in OC)
The “Spacing (in OC)” value used in this tool’s formula. Adjust it to see results update live.
Bar weight (lb/ft)
The “Bar weight (lb/ft)” value used in this tool’s formula. Adjust it to see results update live.
How this calculator works
Rebar pieces and weight for a slab or footing run. Planning estimates only — verify measurements and local codes on site. Pieces = length ÷ spacing + 1; weight = pieces × length × lb/ft. Example: 40 ft run, 12 in spacing, #4 bar → 41 sticks, ~164 ft, ~110 lbs.
Pieces = length ÷ spacing + 1; weight = pieces × length × lb/ft.
Example: 40 ft run, 12 in spacing, #4 bar → 41 sticks, ~164 ft, ~110 lbs.
When to use this Rebar Spacing & Weight
Common use cases
- Rebar pieces and weight for a slab or footing run.
- Sanity-check with this case: 40 ft run, 12 in spacing, #4 bar → 41 sticks, ~164 ft, ~110 lbs.
- The relationship is: Pieces = length ÷ spacing + 1; weight = pieces × length × lb/ft.
Localized examples
- Masonry & Concrete: the example on this page uses the same formula as the widget.
What you get
- Fields: Run length (ft), Spacing (in OC), Bar weight (lb/ft)
- Pieces = length ÷ spacing + 1; weight = pieces × length × lb/ft.
- Example on the page: 40 ft run, 12 in spacing, #4 bar → 41 sticks, ~164 ft, ~110 lbs.
How to Calculate Rebar Spacing & Weight Step-by-Step
- 1Enter Run length (ft), Spacing (in OC), Bar weight (lb/ft). Use the values you have, not a catalog average, unless that is all you know.
- 2Pieces = length ÷ spacing + 1; weight = pieces × length × lb/ft.
- 3Worked case: 40 ft run, 12 in spacing, #4 bar → 41 sticks, ~164 ft, ~110 lbs.
- 4Buy materials after you walk the job. This is a first-pass quantity, not a purchase order.
Governing formula
Pieces = length ÷ spacing + 1; weight = pieces × length × lb/ft.
40 ft run, 12 in spacing, #4 bar → 41 sticks, ~164 ft, ~110 lbs.
Example: set Run length (ft) = 40, Spacing (in OC) = 12, Bar weight (lb/ft) = 0.668, then read the result.
Variable definitions
- runLengthFt
Run length (ft)
The “Run length (ft)” field. Default 40; typical range 5–500.
- spacingIn
Spacing (in OC)
The “Spacing (in OC)” field. Default 12; typical range 6–24.
- barWeightLbPerFt
Bar weight (lb/ft)
The “Bar weight (lb/ft)” field. Default 0.668; typical range 0.2–2.
- The takeoff (Pieces = length ÷ spacing + 1; weight = pieces × length × lb/ft.) ignores waste, code, and what you find when you open the wall. Measure twice on site.
- Nothing here is uploaded for the calculation itself.
Frequently Asked Questions
Pieces = length ÷ spacing + 1; weight = pieces × length × lb/ft.
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Reviews & Ratings
See what others think about this tool, then leave your own rating to help improve CalculioHub.
4.8
out of 5.0
4 reviews
Daniel R.
Feb 28, 2026
Very usable on mobile. Would love a save/export option later, but the math feels solid.
Priya S.
Feb 3, 2026
The FAQ section answered my questions before I even had to search. Smooth dark mode too.
Marcus L.
Jan 19, 2026
Simple inputs, clear outputs. This replaced three bookmarks I used to juggle.
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