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Same problem as another thread: Field Calculator returning incorrect length and area values

Trying to calculate length of a line shapefile, and field calculator is returning values that are way too high (by factor of 1000 or more, like the thread above). Both the shapefile and the project are projected in NAD83 / North Carolina (ftUS) - so they are consistent. The preview shows lengths that appear correct/reasonable, but then the calculated value that is returned is way off.

See attached image - shows that output preview looks right, but then the calculated values (to the right) are way higher and don't match the output preview.enter image description here

Any suggestions?

  • What is the field type for QGISlength? Is it integer? If it is, what happens if you make it a double? – mkennedy Jan 22 '15 at 0:52
  • Welcome to GIS SE. This might be a silly question, but could it be a m-to-km conversion problem? (You mentioned a factor of 1000.) – Martin F Jan 22 '15 at 3:17
  • Field type is integer, but same thing happens when I make it a decimal. – Lynnette Batt Jan 26 '15 at 1:30
  • I'm not sure how it could be m to km conversion problem, as the scale is too far off in the high direction (suggesting it would be calculating it in what... centimeters? :) – Lynnette Batt Jan 26 '15 at 1:31

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