Units (R3UNITS)

Command: R3UNITS

Opens the R3Survey unit settings dialog. These settings control how distances, areas, and angles are entered and displayed across all R3Survey commands.

See Units for a full explanation of unit types and conversion factors.

The three unit concepts

Concept	Meaning
Drawing units	What one model-space unit represents (e.g. 1 drawing unit = 1 metre). This is the internal storage unit.
Input units	The unit you type in R3Survey commands (e.g. feet and inches). R3Survey converts to drawing units automatically.
Display formatting	How values are shown in the UI, R3PROPERTIES, and annotation. Display settings never change stored geometry.

These are independent. You can draw in metres, enter distances in feet and inches, and display results in links — R3Survey converts everything automatically.

Form tabs

The dialog has four tabs: Length, Angles, Area, and Custom Units.

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Length tab

Drawing Length Units

Defines what one model-space unit represents (e.g. metres, feet, links, US survey feet). Set this to match your drawing.

Input Units

The default unit used when entering distances in R3TRAV and R3OFFSET. Can also be switched dynamically during those commands (m, f, e, u, l).

Unit	Description
Metres	SI metric
Feet and inches	Imperial, entered in feet.inches-numerator/denominator format
Decimal feet	International feet, decimal
US survey feet	US customary feet
Links	Survey chains (1 chain = 100 links = 20.1168 m)
Custom	User-defined conversion factor

Display settings

• Display precision — number of decimal places shown in the UI
• Metric/Decimal rounding — rounds displayed values (set to 0 to disable; e.g. 0.005 rounds to nearest 5 mm)
• Rounding units — the unit the rounding value is expressed in
• Feet & Inches rounding — rounding fraction for displayed feet and inches values (e.g. nearest ¼ inch)
• Trim trailing zeros — removes trailing zeros (e.g. 35.500 → 35.5)
• Rounding method — fixed rounding value or significant figures

Display precision and traverse entry

When entering the next traverse leg, R3TRAV pre-fills the previous distance using the current display precision. Accepting that pre-filled value creates the leg at the displayed (rounded) value. Set display precision to match the number of decimal places you need for input.

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Angles tab

Angle Units

Choose the format for bearing entry and display:

Option	Format	Example
North Azimuths (DMS)	Whole-circle, degrees-minutes-seconds	215°35'45"
Surveyor's Bearings	Quadrantal (N/S toward E/W)	S 45°21'35" E
Gradians / Gons	Whole-circle, 400g per revolution	385.7184 g
Decimal Degrees	Whole-circle, decimal	215.8921°

R3Survey uses its own angle engine and ignores AutoCAD's UNITS angle settings.

Display Format

Controls how angle values are presented:

Format	Example	Applies to
Compact	215°35'45"	DMS and Surveyor's Bearings
Spaced	215° 35' 45"	DMS and Surveyor's Bearings
Decimal	215.3525	All angle types

Other angle settings

• Angle precision — decimal places shown for seconds (or decimal degrees). Affects R3PROPERTIES, R3TRAV form, and all angle displays.
• Angle rounding — rounding applied to annotation outputs (bearing text placed in the drawing). Does not affect R3PROPERTIES or R3TRAV prompts. Set to 0 to disable.
• Trim trailing / leading zeros — controls zero trimming in displayed angle values.

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Area tab

Display settings

• Drawing Area Units — automatically set based on drawing length units
• Display precision — decimal places for area values
• Metric/Decimal rounding — rounding for displayed areas (e.g. 1 rounds to nearest m²)
• Imperial Area rounding — rounding fraction for Acres/Roods/Perches display
• Trim trailing zeros, Thousand separators, Digit grouping — formatting options

Area units available include: square metres, hectares, square feet, acres, square chains, perches, and custom units.

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Custom Units tab

Define custom length and area units using a conversion factor relative to metres (for length) or square metres (for area). Any unit used anywhere in the world can be defined this way — historic units, regional systems, or project-specific units.

Custom units appear alongside built-in units in all input and display dropdowns.

Known issue

Editing a custom length unit resets the current input unit to metres. Set the input unit again after editing a custom unit.

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Notes

• Unit settings are persisted between sessions
• Display unit changes in R3UNITS are reflected immediately in an open R3PROPERTIES panel
• Input and display units are independent — you can enter in links and display in metres simultaneously
• AutoCAD's LUNITS, ANGTYPE, ANGBASE, and clockwise/counterclockwise settings are ignored by R3Survey