A free, web-based toolkit built for AutoCAD drafters at every level. Every page handles one specific part of the scaling and units workflow — look it up, grab the number, and get back to drawing. No account, no installation, works offline once loaded.
DIST command to measure a known real-world dimension. If AutoCAD's number doesn't match reality, you have a unit or scale mismatch — go back to INSUNITS and UNITS.1/48xp. Locks your view to the exact drawing scale.Architectural / Imperial: Scales written as "1/4 inch = 1 foot" mean 1/4" on paper = 12" in real life. The SF is 48 (= 12 ÷ 0.25). One drawing unit = 1 inch.
Civil / Engineering: Scales written as "1 inch = 50 feet" mean 1" on paper = 50' in real life. One drawing unit = 1 foot. The SF is 50. If units were in inches instead, SF would be 600 (50 × 12).
Metric: Scales written as 1:100 mean 1 mm on paper = 100 mm in real life. The SF is simply the second number (100). One drawing unit = 1 mm.
| Variable | Type / Alias | What It Does | What to Set It To |
|---|---|---|---|
UNITS | Dialog / UN | Sets drawing unit type, precision, and insertion scale. Start every new drawing here. | Your discipline: Architectural, Engineering, Decimal, Metric |
INSUNITS | Integer 0–20 | Controls auto-scaling when inserting blocks or XREFs. Critical for mixing metric and imperial files. | 1 = inches, 4 = mm, 6 = meters. Set once per drawing. |
MEASUREMENT | 0 or 1 | Selects which linetype and hatch pattern library AutoCAD loads (imperial vs metric). | 0 = imperial, 1 = metric |
LTSCALE | Decimal number | Global linetype scale. Controls how dashed/hidden lines look. Wrong value = dashes too big or invisible. | = your Scale Factor (SF) |
PSLTSCALE | 0 or 1 | Makes linetype scale relative to viewport scale in Paper Space. Keep at 1 — makes linetypes look right in all viewports. | 1 (default — keep here) |
DIMSCALE | Decimal number | Scales all dimension components: arrows, gaps, text, ticks. Set equal to SF for non-annotative dimensions. | = your Scale Factor (SF) |
CANNOSCALE | Scale string | Active annotation scale. Must match your viewport scale when using annotative objects. | Match to viewport scale, e.g. "1/4" = 1'" |
HPSCALE | Decimal number | Default hatch pattern scale. Set equal to your Scale Factor so hatch spacing looks correct when plotted. | = your Scale Factor (SF) |
AutoCAD doesn't know inches from millimeters — it just knows numbers. "1 drawing unit" means whatever you tell it to mean when you set INSUNITS and UNITS. This is the single biggest conceptual hurdle for new drafters.
| Discipline | 1 Unit = | INSUNITS | Display Format | Example: Draw a 30' wall |
|---|---|---|---|---|
| Architectural | 1 inch | 1 | 1'-6" (feet-inches) | Type 360 (30 ft × 12 in) |
| Engineering | 1 inch | 1 | 1'-6.000" (decimal feet-in) | Type 360 |
| Civil / Survey | 1 foot | 2 | 30.0000 (decimal feet) | Type 30 |
| Metric | 1 mm | 4 | 9144.0000 (decimal mm) | Type 9144 (30 ft in mm) |
| Metric (large) | 1 meter | 6 | 9.1440 (decimal m) | Type 9.144 (30 ft in m) |
Both Architectural and Engineering units use 1 unit = 1 inch, but they display the same distance differently:
Pick a discipline and scale from the dropdowns — the results panel fills in every value you need in one shot. No math required.
1/48xp)Two input panels — Metric (left) and Imperial (right). Type any value into any field and all others update instantly. The orange Nearest Fraction panel shows the closest standard fraction to any decimal you enter, with a green ✓ when it's exact.
768 rows covering every 1/64" increment from 1/64" to 12". Color-coded by fraction denomination. Jump buttons skip directly to any whole inch. Type any fraction, decimal, or mm value in the search box to filter live.
HPSCALE = Scale Factor in most cases, but some hatch patterns have a base scale built in that requires adjustment. The calculator handles the pattern-specific math for you — enter your drawing scale and the pattern name to get the correct HPSCALE.
Guided step-by-step flow for new drawings. You answer questions about discipline, paper size, and scale — the wizard builds the complete command sequence. Copy and paste straight into AutoCAD:
Covers the full layout-to-print workflow. If Scale Calculator tells you what your numbers are, this page tells you where to put them:
Annotative objects scale themselves automatically based on the viewport's annotation scale setting (CANNOSCALE). One text or dimension object can display at the correct size in multiple viewports at different scales simultaneously. The page covers setup, the CANNOSCALE workflow, and common annotative vs non-annotative comparison.
Layer naming follows industry standards (AIA, NCS) so every drafter on a project team can instantly recognize what's on a layer. The page provides color-coded tables for Architectural, Civil, Electrical, Mechanical, and Structural disciplines. Each layer entry shows name format, color number, linetype, and lineweight.
Shows every standard AutoCAD linetype with a visual preview of its dash-dot pattern and the correct LTSCALE to use at each common drawing scale. Covers both imperial and metric pattern files (.lin). If your hidden lines print as solid, or your centerlines have no pattern visible, this page diagnoses it.
The most misunderstood concept in AutoCAD, explained step by step with diagrams. Covers: creating viewports (MVIEW), setting scale (zoom XP), locking, VPLAYER per-viewport layer freeze, viewport clipping, multiple viewports at different scales on one sheet, and PSLTSCALE.
DIMSTYLE controls every visual aspect of dimensions: arrow type and size, text height and position, extension line gaps, tolerances, and units. The page covers setting DIMSCALE vs using annotative dimensions, creating a firm-standard style, and overriding individual dimension properties without breaking the parent style.
Searchable reference of all 100+ standard AutoCAD command aliases organized by category: Draw, Modify, Dimension, View, Layer, Block, and Settings. Shows both the alias (e.g., L) and the full command (LINE) with a short description. Learning 20–30 key aliases cuts drafting time significantly.
Xrefs let you link one drawing into another as a live reference — the host drawing always reflects the latest saved version of the source. Key concepts covered on the page:
SSM organizes an entire drawing set as a project, not just individual files. Three-tab interactive panel with step-by-step guide:
Three-tab interactive reference:
Everything about getting a clean print:
This app is a Progressive Web App (PWA) — it can be installed directly to your iPhone or Android home screen and used like a native app, with no App Store required.
Once you've visited the app at least once, the service worker caches all 36 pages, icons, and the PDF reference card to your device. After that, the app works with no internet connection — useful on a job site with spotty signal.
Every page is fully responsive. On iPhone 17 Pro Max and similar large phones, the navigation uses a hamburger menu (☰) — tap it to expand the full list of 37 tools, then tap any link to navigate. Tables become horizontally scrollable. All interactive elements meet the 44px minimum touch target size for comfortable use with a stylus or gloves.
Press Ctrl+P (Windows) or Cmd+P (Mac) on any page. The navigation, buttons, and dark mode chrome are automatically hidden, leaving a clean ink-friendly version of the content with color coding preserved.
The Search page indexes all 37 tools by keywords, command names, and concepts. Type any of the following and it finds the right page instantly:
Filter results by category (Calculator, Guide, Reference) using the pill buttons above the results. Results show the tool icon, name, a description, and tag chips — click any result card to open that tool.