Geometry and layout calculator
Scale Drawing Calculator
Convert a measurement between a drawing and the real object without reversing the scale.
What the result means
A 1:4 drawing is one quarter of the real size. The direction matters. Multiplying when you should divide is the most common error.
Formula
Actual size equals drawing size multiplied by the actual scale part, then divided by the drawing scale part.
Common mistakes
- Reversing the two parts of the scale.
- Assuming a printer kept the drawing at its original size.
- Using a length scale to calculate area or volume.
Before you use the result
This calculator performs the math using the information you enter. Check the measurements and make sure the result fits the actual project before cutting, drilling, buying materials, or putting anything into service.