Scale Calculator
Choose a standard architectural drawing scale, slide the measurement on the drawing — instantly see the real-world size and what kind of drawing that scale is typically used for.
A door 1 m wide is drawn on paper, at this scale, as .
This is a simple unit-conversion tool based on standard architectural drawing scales; it is not tied to any regulation or approval process. The "typical use" column reflects a general drawing convention and can vary by project.
How do you read scale on an architectural drawing?
A scale note like "1:50" or "1:200" on an architectural drawing shows how many real-world units correspond to one unit on the drawing. On a 1:50 plan, for instance, 1 cm on the drawing equals 50 cm (half a meter) in reality.
The tool above converts a distance you've measured on a drawing (mm) to real size based on the scale you choose, and shows which type of drawing that scale is typically used for in architecture.
What each scale is used for
Large scales like 1:20 are used for small but high-precision elements such as a staircase step or a window detail. 1:50 is the most common scale for a floor plan or section of an apartment or house — furniture layout and room dimensions stay legible at this scale.
1:100 and 1:200 are used to show an entire building or several floors on a single page; 1:500 is preferred for broader drawings like a site plan, which shows the building in relation to its surroundings.
Why this isn't a regulatory matter
Scale selection is a matter of drawing practice, not zoning regulation — which scale to use is a choice made by the architect (or a project's drawing standard) based on the drawing's purpose and legibility needs. The "typical use" matches in this tool reflect a general convention, not a strict rule.
Let's talk about which stage of your project needs which scale of drawing.
Contact usFrequently Asked Questions
On a 1:50 drawing, how many meters does 1 cm represent in reality?
At 1:50 scale, 1 cm on the drawing equals 50 cm (half a meter) in reality. General formula: real length = drawing length × scale denominator.
What scale are house plans usually drawn at?
1:50 is the most common scale for residential plan and section drawings — it keeps room dimensions and furniture layout clearly legible. 1:100 is also common for larger buildings or floor plans.
Why is a site plan drawn at a smaller scale like 1:500?
A site plan needs to show the building together with its entire plot and surroundings, so a smaller scale (like 1:500) is used to fit a wider area on one page — detail clarity isn't the priority there.