Hi all, My question may be stupid but I could not find the unit for my polygon area after the calculation.

1 month ago 14 Replies
TN
Trinh Nguyen
3 years ago

Hi all,

My question may be stupid but I could not find the unit for my polygon area after the calculation. It gave me a number without unit (e.g. m2, ha, etc.).
I google and some said check the unit of the coordinate system in Properties->General (or in Metadata), but it seems that my version does not have General tab on Properties. I am using Qgis 3.10.

My coordinate system is epsg4326 wgs84.

Any advice? Thanks all!

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Replies

George Cabrera 3 years ago

4326 has its units set as degrees.

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Trinh Nguyen (3 years ago)

Thanks George Cabrera: actually How to convert degrees to common area unit (m2 or ha) in QGis?

Robbie Austrums 3 years ago

Project Properties > General > Units for area measurement

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Trinh Nguyen (3 years ago)

Thanks. Will try later. What I did was right click on the working layer and go to Properties, where I could not find “General”. I guess your “Project Properties” is a different thing.

Robbie Austrums (3 years ago)

Yes, in the Project menu at the top left of the QGIS window.

Trinh Nguyen (3 years ago)

It said m and m2. Does that mean my polygon area unit is by default m2? Any conversion needed?

Kelvin Manda Kantikana (3 years ago)

Yes try this!!!

Trinh Nguyen (3 years ago)

I solved it! thanks!

Deepan Kaviarasu 3 years ago

Export the polygon in 3857 projection... then the area will be calculated in m2

2 Likes
Trinh Nguyen (3 years ago)

Thanks, will try later :)

Trinh Nguyen (3 years ago)

There are Geographic coordinate system and Projected coordinate system and they contain so many options, could you please indicate the full and correct 3857 one? Also I assume it is: right lick on layer->export->save feature as... am I correct?

Deepan Kaviarasu (3 years ago)

Trinh Nguyen projected coordinate system 3857 .... projected coordinate system basically give measurement in m2,ft2 etc and geographic coordinates units are degrees

Trinh Nguyen (3 years ago)

Thanks I solved it.

Eyira Alby 3 years ago

If your input data is in decimals, then it's m2

1 Like