Rebar Weight Calculator
Calculate the weight of rebar: enter the bar size and total length to get total weight, using standard bar weights per foot (#3 through #11).
How this calculator works
Rebar comes in standard sizes, and each size has a fixed weight for every foot of length. This calculator takes the bar size you pick and the total length you enter, then multiplies the length by that bar’s published weight per foot to give you a total weight in pounds.
The bar number is a quick shorthand for diameter: it is the diameter measured in eighths of an inch. A #4 bar is 4/8 in, which is 1/2 in, and a #8 bar is a full inch. Bigger numbers mean thicker bars, and thicker bars weigh more per foot.
Formula: Total weight = length (ft) × the bar’s weight per foot.
Worked example
A run of #4 bar, 100 ft total:
- Bar size: #4 (1/2 in diameter)
- Weight per foot: 0.668 lb/ft
- Total: 100 × 0.668 = 66.8 lb
Reference
Rebar weight per foot:
| Bar size | Weight per foot | 100 ft |
|---|---|---|
| #3 | 0.376 lb/ft | 37.6 lb |
| #4 | 0.668 lb/ft | 66.8 lb |
| #5 | 1.043 lb/ft | 104.3 lb |
| #6 | 1.502 lb/ft | 150.2 lb |
| #7 | 2.044 lb/ft | 204.4 lb |
| #8 | 2.670 lb/ft | 267.0 lb |
| #9 | 3.400 lb/ft | 340.0 lb |
| #10 | 4.303 lb/ft | 430.3 lb |
| #11 | 5.313 lb/ft | 531.3 lb |
How to use
Pick your bar size from the standard range (#3 through #11) and enter the total length of all bars of that size combined. Read off the total weight, and if your project mixes sizes, run each size on its own and add the results for your full material order.
Weights are estimates based on typical densities. Actual weight varies with moisture, mix design, and material grade — confirm with your supplier.
Frequently asked questions
What does the rebar bar number actually mean?
The bar number is the diameter measured in eighths of an inch. A #4 bar is 4/8 in, which equals 1/2 in. A #8 bar is 8/8 in, or a full 1 in. This holds across the standard range, so the number gives you the diameter at a glance without a chart.
Why does rebar weight matter for a project?
Rebar is often priced and shipped by weight, so knowing the total pounds helps you estimate cost and plan handling. A large mat of heavy bars adds up quickly, which affects how much you order and how you move it on site. Weight also matters when a supplier quotes per pound rather than per length.
How do I find the total length to enter?
Add up the length of every bar of the same size in your layout. If you have ten #5 bars at twenty feet each, your total length is two hundred feet. Calculate each bar size separately, since each size has its own weight per foot, then combine the totals for your full order.
Does this weight include hooks, bends, or laps?
The weight follows the straight length you enter, so any extra material from hooks, bends, or lap splices should be included in that length. Measure the developed length of each bent bar, not just the straight span, and add lap lengths where bars overlap, so the weight reflects what you will actually buy.
Estimates only. Verify quantities with your supplier before purchasing.