Scale Conversion Calculator

Convert between scale and real-world dimensions for architectural, engineering, and model scales with metric and imperial support.

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Enter a measurement Provide a positive measurement value and scale ratio to convert.

Also in Dimensions & Conversions

Scale & Proportion

Convert between scale dimensions and real-world measurements

A scale conversion calculator translates between a scaled drawing or model dimension and the corresponding real-world measurement. It supports common architectural, engineering, and model-building scales and works in both metric and imperial units.

How scale conversion works

A scale ratio such as 1:50 means that one unit on the drawing equals 50 of the same units in reality. To find the real-world measurement, multiply the drawing measurement by the scale factor. To find the drawing measurement, divide the real-world measurement by the scale factor.

The calculator handles both directions and converts the result to multiple units so the output is compatible with whatever measuring tools are available.

Real size = Scale size x Scale factor

Multiply the measurement on the drawing or model by the scale factor to get the actual size.

Scale size = Real size / Scale factor

Divide the real-world measurement by the scale factor to get the dimension to draw or build.

Common scales

Architectural drawings commonly use 1:50, 1:100, or 1:200 in metric countries, or scales like 1/4 inch equals 1 foot in imperial. Model building uses scales such as 1:24, 1:48, 1:72, and 1:144. Engineering site plans often use 1:500 or 1:1000.

Frequently asked questions

What does a 1:50 scale mean?

It means that 1 unit on the drawing represents 50 of the same units in reality. A line measuring 2 centimetres on a 1:50 drawing represents 100 centimetres (1 metre) in the real world.

How do I convert between imperial architectural scales and ratios?

An imperial scale like 1/4 inch equals 1 foot is equivalent to a 1:48 ratio. The calculator handles this conversion automatically for common architectural and engineering scales.

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