What is a slab edge offset?

It is the specified horizontal distance from a slab edge to a feature such as a gridline, column center or opening reference.

Can I calculate offsets from opposite edges?

Yes. Enter offsets from two edges to obtain the remaining intermediate dimension.

Does this determine structural slab dimensions?

No. It performs dimensional setout calculations only.

Slab layout geometry

Slab Edge Offset Calculator

Calculate feature positions from slab edges and instantly see the remaining dimension between opposing offsets.

Slab dimensions

Slab length

Slab width

Offset from left edge

Offset from right edge

Offset from lower edge

Offset from upper edge

Unit

Enter slab dimensions and edge offsets.

Offset positions

Available intermediate span——

—X feature position

—Y feature position

—X remaining

—Y remaining

—

Offset method

The feature position from an edge equals the entered offset. Where two opposing offsets are supplied, the remaining distance is the slab dimension minus both offsets.

X remaining = slab length − left offset − right offset
Y remaining = slab width − lower offset − upper offset

Example

A 20 m slab with 2 m left and 3 m right offsets leaves 15 m between those reference positions. A 12 m slab width with 1.5 m and 2 m offsets leaves 8.5 m.

Edge-case warning

If opposing offsets exceed the slab dimension, there is no physical room between the stated reference positions. The tool flags that condition rather than returning a misleading negative “clear” span.

Frequently Asked Questions

Can one offset be zero?

Yes.

Is the result a structural dimension?

No. It is a geometric setout value.

Can this locate multiple features?

For multiple features, use each feature's own offset and keep the coordinate schedule separate.