Scale Calculator
Enter a scale ratio (1:N) to convert between drawing or model distance and real-world distance.
Drawing/model distance → Real distance
Real distance → Drawing/model distance
Enter both distances in the same unit (e.g. both in cm, or both in meters) — the scale ratio itself is unitless.
How scale ratios work
A scale of 1:N means that 1 unit of length on the drawing, map, or model represents N of that same unit in real life. For example, a 1:100 architectural scale means 1 cm on the plan equals 100 cm (1 meter) in the actual building.
To go from drawing distance to real distance, multiply by N. To go from real distance to drawing distance, divide by N. Both calculations use the same scale value, just in opposite directions.
Frequently asked questions
What does a 1:50 scale mean?
It means every 1 unit of length on the drawing or model represents 50 of that same unit in reality — so 2 cm on a 1:50 plan represents 100 cm (1 meter) in real life.
How do I find the scale if I know both distances?
Divide the real distance by the drawing distance (in the same units) to get N, then express it as 1:N.
Does it matter what unit I use?
No, as long as you use the same unit for both the drawing/model distance and the real distance — the scale ratio itself works the same regardless of whether you're measuring in centimeters, inches, or any other unit.