OS Terrain 50

Visualise simple landscapes in 3D and bring your geographic analysis to life.


Make better decisions about where to locate wind turbines and mobile phone. OS Terrain lets you model wind direction and lines of sight at your desk, meaning fewer site visits.

Get the bigger picture about flood risk, soil erosion and pollution. By showing steep hillside gradients, OS Terrain 50 helps you plan flood defences and safeguard the landscape.

Save money and benefit from simple licensing terms. OS Terrain 50 is free to view, download and use for commercial, education and personal purposes.

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More engaging maps

With the contours version of OS Terrain 50, you can shade in hills to show their height. This extra sense of depth is ideal for walking maps and apps.

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Landscapes laid bare

Get an accurate, uncluttered view of the terrain with the grid version of OS Terrain 50. Its 50-metre post spacing gives you a surface model of the entire landscape, including major roads, large lakes and estuaries.

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Taking account of tides

The contours dataset also includes mean high and low water boundaries.

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Need more detail?

If you need a more detailed height dataset for precision analysis, we recommend OS Terrain 5. It maps the landscape at a higher resolution.


Key featuresWhat this product offers

Grid points (DTM grid); Vector points and lines (Contours)

Data structure

GML 3.2 and ASCII (DTM grid); GML 3.2 and Esri shapefile (Contours)


Post spacing of 50m (DTM grid); Vertical interval of 10m (Contours)

Tile size

10km x 10km


1:50 000



Update frequency

Once a year, in July


Great Britain

OS Terrain 50 support ›


How is this data supplied and what do I need to use it?

OS Terrain 50 is available either by download or on DVD. You'll need geographic information system (GIS) software to use it for spatial analysis.

Does OS Terrain 50 contain any third-party data?

No, the source data was captured by OS Integrated Capture Programme suppliers and is our intellectual property.

Why isn’t the sea represented as a single height value?

In OS Terrain 50, the mean high and mean low water lines have been assigned constant height values, based on the average for each tile from information sourced from tide tables. These values have been continued offshore up to the tile edge to ensure consistency (but do not affect the onshore values).

Due to local tidal conditions, the height of the mean high and low water mark varies continuously around the coast of Britain. Inevitably, this means that there can be a step from the tidal area between adjacent tiles.

If you wish to remove this detailed information and apply other values for the sea, you can select the mean high and low water boundaries from the contour product and use them as a bounding box.

See all FAQs for OS Terrain 50 ›


OS Terrain 50 is available under the following Licences:

Our open data products are covered by the Open Government Licence (OGL), which allows you to:

  • copy, distribute and transmit the data;
  • adapt the data; and
  • exploit the data commercially, whether by sub-licensing it, combining it with other data, or including it in your own product or application.

We simply ask that you acknowledge the copyright and the source of the data by including the following attribution statement:

  • Contains OS data © Crown copyright and database right 2018
  • Where you use Code-Point Open data, you must also use the following attribution statements:
  • Contains Royal Mail data © Royal Mail copyright and Database right 2018
  • Contains National Statistics data © Crown copyright and database right 2018

Read more about Open Data licences

View all licences ›

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