Scale and measurement

Scale converts page-space geometry into real lengths, areas and coverage. It is required for cable/pipe totals, ruler measurements, area values and device coverage overlays. Detection counts themselves do not require scale.

Scope and permissions

Scale is stored per page. A scale on page 2 does not apply to page 3, even when both sheets display the same printed ratio. Any user can read the scale; saving or replacing it requires project editing permission.

There are two equivalent UI paths:

project dashboard → page Cables & pipes → Set scale;
page Review & count → Calibrate.

Calibrate from a known distance

Prefer a dimension line or long, clearly identified grid distance. A longer reference reduces click error.

Open the exact page to calibrate.
Select Set scale or Calibrate.
Click the first endpoint of the known distance.
Click the second endpoint.
Enter the real length when prompted.
Confirm that the scale status shows a saved points-per-foot value.
Measure a different labelled distance as an independent check.

Accepted practical forms include feet/inches (12' 6"), decimal feet (12.5 ft) and metric (3.8 m). The application stores a normalized points-per-foot ratio and displays results according to the project's Units setting in Cables & pipes.

Metric and imperial display

Changing Units between imperial and metric changes presentation and input/output conversion; it does not redraw the geometry. Internally, the saved scale can still be represented in points per foot. Enter the unit explicitly when the prompt could be ambiguous.

Cable settings apply project-wide, but scale remains page-specific. Calibrate every sheet that contributes lengths or areas.

Verify with Ruler or Measure

In Cables & pipes:

choose Ruler;
click along the verification line;
double-click or press Enter to finish;
compare the displayed length with the printed dimension.

In Review & count, choose Measure, click successive points and double-click/Enter to finish. Backspace clears the current measurement. This ruler is temporary and does not create a cable run.

If the check is wrong, recalibrate rather than applying an estimate-wide correction factor.

Effects of changing scale

Stored paths and polygons retain their page coordinates. Replacing the page scale recalculates their real-world lengths and areas from those coordinates. Coverage radius overlays also redraw using the new ratio. Therefore a late scale change can alter BOM/estimate run quantities and exports; re-review them before issue.

An unscaled cable or pipe path is saved but its length appears as No scale (or equivalent) and is omitted from numeric totals until scale exists. An unscaled area similarly lacks a square-foot/square-metre result.

Common mistakes

Using the title-block ratio

A PDF may have been resized, cropped or printed to fit. Treat 1/8" = 1'-0" as a clue, not proof. Calibrate against actual dimension endpoints in the processed page.

Calibrating to a short object

A one-foot object makes a few pixels of click error significant. Use a long wall/grid dimension whenever possible.

Mixing units

If the drawing says 3600 mm, enter 3.6 m, not bare 3600. If the result is off by roughly 3.28, check metre/foot interpretation.

Calibrating the wrong page

The scale status belongs to the current page. Use the page selector and verify the displayed sheet name before tracing.

Using perspective or skewed scans

A photographed or non-uniformly stretched plan can have different apparent scales across the page. One linear calibration cannot correct perspective distortion. Use a properly scanned PDF or divide/verify measurements manually; do not assume area totals are reliable.

Recovery checklist

If totals are blank or implausible:

confirm the page is enabled;
confirm Scale is set on that page;
measure a known second dimension;
verify the unit entered and the Units display setting;
check that the path follows the intended route and includes/excludes vertical drops correctly;
recalibrate and re-open the estimate/export.