🗺️Scale Calculator

Scale calculator for maps and models — how to convert distances

A scale is the ratio of the length on a drawing to the real length. The scale calculator lets you instantly work out the real-world distance from a measurement on a map — or the reverse: how large a model to build to represent an object at a chosen scale. Simply enter the scale denominator (e.g. 100 for scale 1:100) and one of the lengths, and the result appears immediately.

Map, plan and model scales — practical examples

Topographic maps use scales such as 1:25,000 or 1:50,000, architectural plans use 1:50 or 1:100, and H0 model railways use 1:87. The calculator supports any value of N: choose a popular preset (1:50, 1:87, 1:100, 1:1000) or enter your own number. You can freely mix units — for example, enter the drawing measurement in millimetres and get the result in metres.

Frequently asked questions

What is a scale on a map or drawing?

A scale specifies how many times larger reality is than its representation on the map or model. Scale 1:100 means that 1 cm on the drawing corresponds to 100 cm (1 m) in reality.

How do I calculate the real distance from a scale?

Multiply the length measured on the map or drawing by the scale denominator. Example: 3 cm on a map at scale 1:50,000 is 3 × 50,000 = 150,000 cm = 1.5 km in reality.

What scales are used in scale modelling?

The most popular model scales are 1:87 (H0 — model railways), 1:72 (aircraft), 1:35 (tanks), 1:43 and 1:18 (cars). The calculator supports any scale — just enter your own value of N.

Does the calculator work with different units?

Yes. You can enter the length on the drawing in millimetres and get the result, for example, in metres. The calculator converts units automatically, supporting mm, cm, m and km.