Quick start
- Choose the rebar size, such as #4 or #5. The size controls weight per foot.
- Enter the length of one bar or cut piece in feet.
- Enter how many matching pieces are in the set.
- Add waste for cuts, lap splices, layout changes, bent bars, and damaged pieces.
Best uses
Best when you already know the bar size and count, and you need a quick weight check before buying, hauling, or comparing supplier numbers.
- Estimate rebar weight for pickup or delivery planning.
- Compare #3, #4, #5, and larger bars.
- Add waste for cut lists and lap planning.
- Convert total pounds to US tons.
What this calculator is solving
The Rebar Weight Calculator estimates pounds and US tons from common US rebar sizes. It helps with ordering, hauling, and checking a cut list before you call a supplier.
Match each input label on the calculator to the bar size, length per piece, matching quantity, and waste cushion from your cut list or slab layout.
The formula in plain language
In plain language: The calculator multiplies length per bar by quantity, adds the waste percent, uses the nominal weight per foot for the selected rebar size, and divides total pounds by 2,000 for US tons. The examples on the page are there so you can compare your inputs with a worked example before copying the answer.
For example, #4 rebar weighs about 0.668 lb per foot. Twelve 20-foot #4 bars make 240 feet. With 10% waste, that becomes 264 adjusted feet. Then 264 x 0.668 = 176.352 lb.
How to read the answer
Use total pounds as the main buying and hauling number. Use adjusted length to check the cut list, weight per foot to check the bar size, and US tons when a supplier or truck limit is listed in tons.
- Total pounds is adjusted length times nominal weight per foot.
- Adjusted length includes length, quantity, and waste percent.
- Weight per foot lets you check whether the chosen bar size matches the supplier chart.
- US tons is total pounds divided by 2,000.
Common mistakes to avoid
Most bad rebar-weight estimates come from using the wrong bar size, forgetting lap or cut waste, or treating weight math like an engineering plan.
- Do not use weight as a substitute for reinforcement design.
- Do not ignore lap length, bar spacing, concrete cover, support chairs, and placement drawings.
- Do not enter a whole cut list as one bar unless every piece has the same length.
- Check supplier bundle weights, coatings, and mill tolerances when exact delivery weight matters.
Quick #4 example
Say your slab list has twelve #4 bars, and each one is 20 feet long. That is 240 feet before waste.
With 10% waste, the adjusted length is 264 feet. #4 is about 0.668 lb per foot, so the result is 176.352 lb, or about 0.088 US tons.
Small weight chart check
The calculator uses common US planning weights: #3 is 0.376 lb/ft, #4 is 0.668 lb/ft, #5 is 1.043 lb/ft, #6 is 1.502 lb/ft, #7 is 2.044 lb/ft, and #8 is 2.670 lb/ft.
If your supplier chart shows a different product, use the supplier number for final ordering. Coatings and bundle packaging can make the delivery ticket slightly different from the simple steel-weight estimate.
Slab grid versus weight
If you already know the count and length, use this page. If you only know slab length, slab width, and bar spacing, use the Rebar Calculator first to estimate the grid.
After you have the grid count, come back here with the bar size and cut length to estimate pounds or tons.
What this does not design
This page does not choose the correct bar size, spacing, cover, lap splice length, grade, or placement. Those choices can affect safety and inspections.
CRSI notes that lap splice length depends on details such as concrete strength, rebar grade, size, and spacing, so use project drawings or a qualified professional when those details matter.
Research and references
These references help check rebar weight-per-foot values, lap-splice limits, unit conversions, and why the page stays focused on useful people-first ordering math.
Worked examples for Rebar Weight Calculator
176.352 lb
270.346 lb
75.2 lb
378.504 lb, about 0.189 tons
FAQ in plain language
When should I use the Rebar Weight Calculator?
Use it when your task matches one of these common needs: Estimate rebar weight for pickup or delivery planning. Compare #3, #4, #5, and larger bars. It works best when you already know the measurements, amounts, units, or options the page asks for.
What is the Rebar Weight Calculator doing with my inputs?
In plain language: The calculator multiplies length per bar by quantity, adds the waste percent, uses the nominal weight per foot for the selected rebar size, and divides total pounds by 2,000 for US tons. The examples on the page are there so you can compare your inputs with a worked example before copying the answer.
What do the main Rebar Weight Calculator inputs mean?
Rebar size: the US bar size, such as #4 or #5, used to choose nominal weight per foot. Length per bar: the length of one straight bar, stock bar, or cut piece in feet. Quantity: how many matching bars or pieces at that length. Waste percent: extra length for cuts, lap splices, layout changes, bent pieces, and damaged bars.
How should I read the Rebar Weight Calculator answer?
Read the headline estimate first, then check the material, waste, coverage, and unit lines. For project tools, the supporting lines are often the difference between a rough idea and a list you can actually shop from.
What should I double-check before trusting the answer?
This is ordering and hauling math only. Nominal weights are planning values, and mill tolerances, coatings, cut lists, lap splices, chairs, bundle rules, bar spacing, concrete cover, inspections, and structural design can change the real order. Also check the unit, scale, mode, and result limit because small input changes can change the answer.
What does #4 rebar mean?
#4 is a common US rebar size with a nominal diameter of 1/2 inch and a planning weight of about 0.668 lb per foot.
How much does #5 rebar weigh per foot?
#5 rebar weighs about 1.043 lb per foot. For example, eight 30-foot #5 bars with 8% waste come out to about 270.35 lb.
Related tools
- Rebar CalculatorEstimate rebar grid counts, linear feet, and stock bars from slab size and spacing.
- Concrete Mesh CalculatorEstimate welded wire mesh sheets for a rectangular concrete slab.
- Concrete CalculatorEstimate slab volume, cubic yards, cubic meters, and common 40, 60, and 80 lb bag counts.
- Concrete Weight CalculatorEstimate concrete weight in pounds and US tons from cubic yards, density, and waste.
Keep exploring
If this guide is close but not exact, these links keep you near the same kind of problem.
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Privacy and copying results
Recent answers stay visible only while you work in the current browser tab. They are not sent to a server.
Use Copy answer when you want to save the inputs and result in notes, homework, a message, or a project list. Check the units, labels, and limits before copying.