CAD Scale Converter
Convert any 1:N CAD scale ratio to the nearest common metric, architectural and engineering scale labels.
Enter your values, then select Calculate.
Runs in your browser. No calculation data is sent to an external service.
What this calculator does
This tool is useful when drawings, consultants or software interfaces use different scale conventions. It keeps the exact ratio visible and shows the nearest standard labels in the other scale families.
Example
For 1:50, the closest common architectural scale is 1/4 inch = 1 foot, which is exactly 1:48. The converter shows the relationship without pretending the two are identical.
How to use the result
- Treat converted architectural/engineering scales as comparisons, not automatic replacements.
- Keep the exact 1:N ratio when scale accuracy matters.
- Use the dedicated architectural calculator when you need plotted inch measurements.
Frequently asked questions
What architectural scale is closest to 1:50?
1/4 inch = 1 foot is the closest common architectural scale, but it is 1:48, not 1:50.
What is 1 inch = 20 feet as a ratio?
It is 1:240.
Can a scale converter fix a metric/imperial drawing?
No. It helps compare scales; units, viewport configuration and drawing standards still need to be correct.
Explore more in CAD Plotting Tools & Calculators.