Hi Ahna,
Sorry for late reply. Yeah I got help from geonet. I used geometry engine object to solve this in my arcgis javascript application. You can find the API reference here. esri/geometry/geometryEngine | API Reference | ArcGIS API for JavaScript 3.21
Here is the snippet:
function calculateAcreage(value) {
var NameString = "<p><b>Field Name:</b> " + value.attributes.Field_Name + '</p>';
var sqft = geometryEngine.geodesicArea(value.geometry, "square-feet");
var squarefeet = number.format(sqft, {places: 1});
var acres = number.format(sqft / 43560, {places: 2});
returnString = NameString + "<p><b>Acres:</b> " + acres + '</p>';
return returnString;
};
This result the polygon field shape.area() that is in sq.ft to Acreage value. Hope this helps. Thanks
Kush