Calculateur d'Armatures — Formule
## How to Calculate Rebar Needed
### Formula
**Bars Along Length = floor(Width / Spacing) + 1**
**Bars Along Width = floor(Length / Spacing) + 1**
Rebar is laid in a grid pattern (both directions). Standard rebar comes in 20-foot lengths. Overlap joints should be at least 24 bar diameters (about 18 inches for #4 rebar). Common sizes are #3 (3/8"), #4 (1/2"), and #5 (5/8").
### Formula
**Bars Along Length = floor(Width / Spacing) + 1**
**Bars Along Width = floor(Length / Spacing) + 1**
Rebar is laid in a grid pattern (both directions). Standard rebar comes in 20-foot lengths. Overlap joints should be at least 24 bar diameters (about 18 inches for #4 rebar). Common sizes are #3 (3/8"), #4 (1/2"), and #5 (5/8").
Exemple Résolu
A 20×20 ft slab with rebar on 18-inch centers, using 20 ft rebar.
- Spacing in feet = 18 / 12 = 1.5 ft
- Bars along length = floor(20 / 1.5) + 1 = 14 bars (each 20 ft long)
- Bars along width = floor(20 / 1.5) + 1 = 14 bars (each 20 ft long)
- Total bars = 14 + 14 = 28 bars
- Total linear feet = 14 × 20 + 14 × 20 = 560 lin ft
- Rebar sticks = 560 / 20 = 28 sticks