AutoCAD scale calculator
Convert architectural scales and calculate viewport scale factors
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The AutoCAD Scale Calculator helps drafters and designers convert between architectural scales and calculate the correct scale factors for AutoCAD viewports and annotations.
Working with architectural scales in CAD can be confusing—is 1/4" = 1'-0" the same as 1:48? What DIMSCALE do I need? This calculator clarifies scale relationships and provides the exact values needed for your drawings.
Enter any architectural scale to see equivalent representations, viewport scale factors, and common CAD settings. The calculator handles both imperial and metric scales.
Features
Everything you need
- Architectural scale conversions
- AutoCAD viewport scale factors
- DIMSCALE and LTSCALE values
- Plot scale calculations
- Imperial and metric support
- Common scale reference chart
- Bidirectional conversions
How it works
Simple workflow
- 1Enter your drawing scale in any format
- 2View the scale as ratio, fraction, and factor
- 3Get recommended DIMSCALE values
- 4Calculate viewport zoom factors
- 5Reference the common scales chart
Use cases
Built for real-world scenarios
Viewport setup
Calculate exact zoom XP factors for paper space viewports at standard architectural scales.
Annotation sizing
Determine DIMSCALE settings so text and dimensions plot at correct sizes.
Scale conversions
Convert between architectural notation (1/4"=1'-0") and decimal scale factors.
Print settings
Set up plot scales to print model space drawings at desired scales.
FAQ
Frequently asked questions
1/4" = 1'-0" equals a scale factor of 1:48. In AutoCAD, this means 1 unit in paper space equals 48 units in model space. For viewports, use zoom scale 1/48XP or 0.020833XP.
Convert the scale to inches: 1/4" = 1'-0" means 0.25 inches = 12 inches. Scale factor = 12/0.25 = 48, so scale is 1:48. For 1/8" = 1'-0": 12/0.125 = 96 (1:96).
DIMSCALE multiplies all dimension sizes in model space. If your viewport is at 1/4" scale (1:48), set DIMSCALE to 48 so dimensions display and plot correctly. Alternatively, use annotative dimensions.
Common scales: 1/8"=1'-0" (1:96) for site plans, 1/4"=1'-0" (1:48) for floor plans, 1/2"=1'-0" (1:24) for elevations, 3/4"=1'-0" (1:16), 1"=1'-0" (1:12), 1-1/2"=1'-0" (1:8) for details, 3"=1'-0" (1:4) for large details.
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We're always looking to improve our calculators. If you have ideas for new features, improvements, or found something that could work better, we'd love to hear from you.
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