# Calculating the surface area

Reported by: Owned by: topaloglubekir@… team normal Plugin measurement

### Description

I have downladed a map of a certain area by JOSM.

Now, I need to calculate the surface area of the region I downloaded. Is there anybody who knows how to calculate the surface area?

### comment:1 Changed 13 months ago by simon04

You mean the area of an object or the area of the downloaded bbox? For the former, you might be interested in ​the ​measurement plugin.

### comment:2 Changed 13 months ago by anonymous

I have selected a rectangle area (including the city Garching - near Munich) on JOSM and downloaded it.

Now, I need the surface area of this whole rectangle.

I used measurement plug in but it behaves in a very weird way. When I select an object (e.q a house), I can see its surface area. That's cool. However, when I select multiple houses, it gives a value that is different than the total of the areas of all selected objects.

Anyways, I need the area of the whole rectangle.
My final goal is to find the household density in the region: (the total number of houses) / (total surface area)

Any help would be highly appreciated.

### comment:3 Changed 13 months ago by simon04

I used measurement plug in but it behaves in a very weird way. When I select an object (e.q a house), I can see its surface area. That's cool. However, when I select multiple houses, it gives a value that is different than the total of the areas of all selected objects.

One may want to further inspect the problem you described. Is the displayed value the size of one of the selected objecs?

Anyways, I need the area of the whole rectangle. My final goal is to find the household density in the region: (the total number of houses) / (total surface area)

As a quick workaround, you could draw a closed way matching the downloaded bbox.

### comment:4 Changed 13 months ago by anonymous

1. The sum of the area displayed for 2 or more objects is not the correct total amount, nor the area of either objects.
1. Good idea. I will try drawing a closed circle and getting its surface area.

Cheers,

### comment:5 Changed 13 months ago by skyper

• Component changed from Core to Plugin measurement
• Resolution set to worksforme
• Status changed from new to closed

Think the measurement plugin should fulfill your needs if working. Please reopen if you need further enhancement.

Problem with more than one closed way selected is already reported: #5416

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