Volume + Rebar + ICF
Calculate concrete volume, bag count, and rebar quantity for poured concrete walls, ICF walls, and retaining walls - all in one tool. This concrete wall calculator deducts ICF foam thickness from core volume and outputs horizontal and vertical rebar totals.
Use this with the concrete cost calculator for full budgets, the concrete bag calculator for small walls, and the concrete column calculator for connected piers.
Switch between Standard Poured Wall, ICF, and Retaining Wall modes with input logic tailored to each wall type.
Deducts EPS foam panel thickness from total wall thickness so the order volume uses the actual concrete core.
Enter horizontal and vertical spacing to get bar counts, total linear footage, and steel weight.
Add door and window openings; the calculator subtracts their concrete volume automatically.
Outputs 60 and 80 lb bag counts and flags when ready-mix delivery is the practical path.
Shows concrete and rebar material cost using editable 2025 average pricing.
Calculator
Choose Standard Poured Wall, ICF Wall, or Retaining Wall. For footings under a wall, pair the result with the deck footing calculator. If you are batching by material ratio, use the concrete mix ratio calculator.
Subtract doors and windows using width x height in inches.
No openings entered.
Concrete Volume
Order volume with 10% waste
bags of 80 lb concrete
Rebar Summary
Cost Estimate (2025 avg)
Wall thickness depends on loading, height, backfill, exposure, and local code. IRC R404.1 sets minimum foundation wall rules, but many jurisdictions amend them.
| Wall Type | Min. Thickness | Typical Thickness | Notes |
|---|---|---|---|
| Basement foundation wall | 8 in | 8-10 in | IRC R404: min 7.5 in for limited wall heights |
| Above-grade exterior wall | 6 in | 6-8 in | Structural load determines thickness |
| Interior partition wall | 4 in | 4-6 in | Non-load-bearing only |
| Retaining wall (<=4 ft) | 8 in | 10-12 in | Footing required; rebar mandatory |
| Retaining wall (4-6 ft) | 10 in | 12-16 in | Engineer review recommended |
| Retaining wall (>6 ft) | Engineer spec | 16 in+ | Structural engineer required |
| ICF wall (residential) | 6 in core | 11 in total | Core is concrete; total includes foam |
| ICF wall (commercial) | 8 in core | 13 in total | Higher seismic and wind loads |
| Garden wall (<=2 ft) | 6 in | 6-8 in | No rebar typically required |
Concrete is strong in compression but weak in tension. Rebar supplies tensile capacity for lateral loads, soil pressure, thermal movement, and cracking control. For walls over 4 feet or any retaining application, rebar is structural, not decorative.
| Wall Application | Horizontal Spacing | Vertical Spacing | Min. Rebar Size | Notes |
|---|---|---|---|---|
| Basement wall (8 in thick) | 18 in | 18 in | #4 | Common residential minimum |
| Retaining wall (<=4 ft) | 12 in | 12 in | #4 | Both faces for thicker walls |
| Retaining wall (4-6 ft) | 12 in | 12 in | #5 | Engineer review |
| ICF wall (6 in core) | 16 in | 16 in | #4 | Confirm manufacturer spec |
| Above-grade exterior wall | 18 in | 18 in | #4 | Seismic zones may require 12 in |
| Garden wall (<=2 ft) | Not required | Not required | - | Low-risk application |
| Rebar Size | Diameter | Weight (lb/lft) | Common Use |
|---|---|---|---|
| #3 | 3/8 in | 0.376 | Light slabs, garden walls |
| #4 | 1/2 in | 0.668 | Standard residential walls |
| #5 | 5/8 in | 1.043 | Retaining walls, heavy footings |
| #6 | 3/4 in | 1.502 | Heavy structural, commercial |
Rebar must be tied, not just placed. Untied bars can shift during the pour, reducing or eliminating the structural contribution of the reinforcement grid.
An ICF wall is not a solid concrete wall. It has an outer EPS foam panel, a concrete core, and an inner EPS foam panel. A standard 6-core ICF system may be 11 inches thick overall, but only 6 inches is concrete.
| Brand / System | Core Width | Foam (each) | Total Wall | R-Value (approx.) |
|---|---|---|---|---|
| Nudura Standard | 6 in | 2.75 in | 11.5 in | R-22 |
| Fox Blocks | 6 in | 2.625 in | 11.25 in | R-23 |
| Logix ICF | 6 in | 2.5 in | 11 in | R-22 |
| Quad-Lock | 6 in | 2.5 in | 11 in | R-22 |
| BuildBlock | 6 in | 2.5 in | 11 in | R-22 |
| Generic 4 in Core | 4 in | 2.5 in | 9 in | R-17 |
| Generic 8 in Core | 8 in | 2.5 in | 13 in | R-22 |
One cubic yard of concrete fills approximately 81 linear feet of 4-inch core wall at 8 feet high, 54 linear feet of 6-inch core wall, or 40 linear feet of 8-inch core wall.
Values are per linear foot of wall with no openings and 10% waste included. Multiply the table value by wall length. Example: 20 ft x 8 ft high x 8 in thick = 20 x 0.217 = 4.34 yd3.
| Wall Height | 6 in Thick | 8 in Thick | 10 in Thick | 12 in Thick | ICF 6 in Core |
|---|---|---|---|---|---|
| 4 ft | 0.081 yd3 | 0.109 yd3 | 0.136 yd3 | 0.163 yd3 | 0.081 yd3 |
| 6 ft | 0.122 yd3 | 0.163 yd3 | 0.204 yd3 | 0.244 yd3 | 0.122 yd3 |
| 8 ft | 0.163 yd3 | 0.217 yd3 | 0.272 yd3 | 0.326 yd3 | 0.163 yd3 |
| 9 ft | 0.183 yd3 | 0.244 yd3 | 0.306 yd3 | 0.367 yd3 | 0.183 yd3 |
| 10 ft | 0.204 yd3 | 0.272 yd3 | 0.340 yd3 | 0.407 yd3 | 0.204 yd3 |
The three wall types in this calculator have different thickness rules. A basement foundation wall commonly needs 8 inches. A retaining wall over 4 feet needs additional thickness plus a footing. An ICF wall's concrete core is 4-8 inches even when the total insulated wall is much thicker.
Every door and window opening reduces concrete volume. On a house foundation, deducting openings can cut the order by 5-15%. Enter each opening width and height so the calculator subtracts the right volume before waste.
Rebar must be placed and tied before the pour. Use the rebar section to calculate horizontal rows, vertical bars, total linear feet, and weight before scheduling ready-mix.
Your concrete order must be based on the core width, typically 6 inches, not the total wall thickness, often 11 inches. Selecting an ICF preset applies the correct core dimension.
Concrete creates serious pressure on forms. For walls over 6 feet tall, limit pour rate and brace forms carefully. ICF systems also have manufacturer-specific pour-rate limits.
Typical volume: 0.217 yd3 per linear foot | ready-mix territory
A standard 8-inch basement wall at 8 feet tall uses about 0.217 cubic yards per linear foot with 10% waste. Deduct window openings and use the rebar output before ordering concrete.
Typical volume: wall plus footing | rebar mandatory
A 4-foot exposed retaining wall with 2 feet of embedment and a 24 x 12 inch footing quickly crosses the ready-mix threshold. Use #4 or #5 rebar at close spacing and get engineering review for taller walls.
Typical volume: 0.183 yd3/lft core only
A 6-core ICF wall needs concrete for the core, not the foam. The ICF mode shows the correct order volume beside the inflated number a standard wall calculator would produce.
Typical volume: bagged concrete practical
A low garden wall is one of the few wall applications where bagged concrete may be practical and rebar may not be required. Use Standard Poured Wall mode and turn rebar off for a simple estimate.
Concrete wall volume depends on length, height, and thickness. A standard 8-inch wall uses about 0.217 cubic yards per linear foot at 8 feet tall with 10% waste. For ICF walls, use only the concrete core width, not total wall thickness. Enter exact dimensions above for volume and bag count.
Minimum thickness depends on wall type and application. Basement foundation walls are commonly 8 inches or thicker, retaining walls under 4 feet often use 8-12 inches, and ICF walls usually use a 4-8 inch concrete core. Local code and engineering requirements control final thickness.
Count horizontal bars by dividing wall height by spacing and adding one. Count vertical bars by dividing wall length by spacing and adding one. Multiply rows by wall length and columns by wall height, then multiply total linear feet by the selected rebar weight per foot.
A poured concrete wall uses temporary forms that are removed after curing. An ICF wall uses permanent EPS foam forms that remain in place as insulation. The concrete core may be the same width, but ICF total wall thickness includes foam that should not be counted as concrete.
Use the concrete core width only. A standard 6-core ICF wall may be 11 inches thick overall, but only 6 inches is concrete. The ICF Wall mode applies the selected system's core width and shows the overestimate avoided by not using total wall thickness.
Yes, for most retaining walls over 2 feet tall. Retaining walls resist lateral soil pressure and bending at the base, so tensile reinforcement matters. The calculator defaults retaining walls to tighter spacing and larger rebar than a standard poured wall.
For walls over 0.5 cubic yards, ready-mix is usually faster and often cheaper once labor is included. The calculator flags projects at 1 cubic yard or more. ICF walls usually need ready-mix and a pump regardless of volume.