Inputs
Formulae Used
- Clear spans:
Lclear = L - 2 × cover,Wclear = W - 2 × cover - Bar counts (no edge bars beyond cover):
nX = \u230A Lclear / sX \u230B + 1,nY = \u230A Wclear / sY \u230B + 1 - Actual spacing if even distribution:
s' = span / (n - 1) - Bar lengths:
\u2113X = W - 2 × cover,\u2113Y = L - 2 × cover - Total bars:
N = layers \u00d7 (nX + nY) - Total length (without perimeter):
\u2113tot = layers \u00d7 (nX\u2113X + nY\u2113Y) - Perimeter bar length (optional):
\u2113perim = layers \u00d7 2(L + W) - Unit weight: metric
kg/m = d^2 / 162; US sizes use typical lb/ft chart. - Splices (optional): per-bar splices
m = \u2308 \u2113 / stock - 1 \u2309, addm \u00d7 lapto each bar length.
These are planning estimates. For structural design, consult a licensed engineer.
How to Use
- Select your unit system and grid mode.
- Enter overall slab length, width, spacing each way, and edge cover.
- Choose bar system and size; optionally set laps, stock length, and waste.
- Pick single or double layers; add a continuous perimeter bar if required.
- Click Calculate. Results show counts, actual spacing, lengths, and weight.
- Use Download CSV or Download PDF to export a report.
- Press Copy Shareable URL to save and share inputs.
Results
Bars in X
-
Bars in Y
-
Actual Spacing X
-
Actual Spacing Y
-
| Metric | Value | Units |
|---|---|---|
| Total Bars | - | - |
| Total Length | - | - |
| Total Weight | - | - |
| Perimeter Length | - | - |
| Stock Splices Added | - | - |
| Waste Added | - | - |
Input Summary
Example Data
| Example | L | W | Spacing X | Spacing Y | Cover | Bar | Layers | Total Bars | Total Length | Weight |
|---|
Click any row to load its values into the form.
FAQs
Common spacings are 6–18 inches (150–450 mm) depending on loads, thickness, and exposure. Always follow project drawings or a licensed engineer’s guidance.
Yes. Switching units updates labels; values are treated numerically. Re-enter if converting physically, or use the same numeric magnitudes in the chosen system.
Cover is the clear distance from concrete surface to steel. It controls durability, corrosion protection, and fire performance, and it shortens bar lengths and clear spans.
When enabled, one continuous bar around the boundary is added per layer: length equals 2(L+W). Cuts at corners aren’t modeled; adjust as needed on site.
If a bar exceeds stock length, each splice adds the specified lap to that bar. The tool sums the additional length for all bars requiring splices.
If “Evenly Distribute” is on, the tool recomputes spacing so the first and last bars land at the set cover and the remainder is uniform.
No. This is for planning and estimating only. Final reinforcing layouts must be designed and stamped by a licensed structural engineer.