Eccentric Isolated Footing Designer (IS 456:2000)

Eccentric Isolated Footing Designer —

IS 456:2000 • Total eccentricity for soil pressure • Physical spans for bending & one-way shear

Input Data

ParametersValueUnit
Column size (a × b) × m
Service axial load NserkN
Service moments (Mx, My) , kN·m
Column position mode —
Physical eccentricities (ex, ey) , m
Concrete grade (fck) MPa
Steel grade (fy) MPa
Suggest geometry (targets 0.95×SBC)—
Footing size (B × L) × m
Footing thickness (t)m
Clear covermm
Bottom bar dia (ϕ) mm
Top bar dia (ϕtop) mm
Dowel bar dia mm
Allowable SBCkN/m²
Eccentricities (ex, ey)
—
qmax / qmin (kN/m²)
—
d (mm) & ρt (%)
—

Codal Checks (IS 456) — OK / Not OK

CheckRule / ClauseUtilization & Key ValuesStatus

Bottom steel: X-direction

ParameterValueUnit
Design moment—kN·m/m
As,x required—mm²/m
Provide—mm²/m

Bottom steel: Y-direction

ParameterValueUnit
Design moment—kN·m/m
As,y required—mm²/m
Provide—mm²/m

Top steel near column (hogging)

ParameterValueUnit
Hogging moment — X—kN·m/m
As,top,x required / provided—mm²/m
Hogging moment — Y—kN·m/m
As,top,y required / provided—mm²/m
Top steel is shown only if computed hogging near the column requires it; otherwise minimum steel (0.12% each way) with matching spacing is displayed.

Design Calculation (preview)




Key to Symbols
  • B: Footing width (X-axis).   L: Footing length (Y-axis).
  • a: Column width (X).   b: Column length (Y).
  • ex: Horizontal center-to-center offset (footing → column).   ey: Vertical C/C offset.
  • Edge dist. (left/right/top/bottom): Edge-to-column face distances.
Important Notes & Disclaimer

This design tool is based on the limit state provisions of IS 456:2000. Please double-check all inputs and the resulting checks before finalizing the design. Results are for informational purposes and must be reviewed and approved by a licensed professional engineer prior to use in construction.
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});/* ============== UI toggles & bindings ============== */
function togglePositionRows(){
const mode = $("colPosMode").value;
const showEcc = (mode==="ecc");
$("row_ecc").style.display = showEcc ? "" : "none";
$("row_edges_lr").style.display = showEcc ? "none" : "";
$("row_edges_tb").style.display = showEcc ? "none" : "";
// clear hidden
if (showEcc) {
$("left_in").value = ""; $("right_in").value = ""; $("top_in").value = ""; $("bottom_in").value = "";
} else {
$("ex_in").value = ""; $("ey_in").value = "";
}
calc();
}
$("colPosMode").addEventListener('change', togglePositionRows);// Bind inputs (recompute on change)
[
"B","L","t","a","b","fck","fy","cover","phi","phiTop","phiDowel","Nser","Mxser","Myser","SBC",
"ex_in","ey_in","left_in","right_in","top_in","bottom_in"
].forEach(id=>{ $(id).addEventListener('input', calc); });// Initial markings (no compute until required fields present)
markRequired(REQ_FOR_CALC);
renderEmptyOutputs();
REQ_HINT.innerHTML='Enter required inputs to begin.';
 
  



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