How many ATP and NADPH molecules will be required to make one molecule of glucose through the Calvin pathway? 

One turn of the calvin cycle can fix only one CO₂, so to make one molecule of glucose, which is a 6 carbon compound, 6 turns of the calvin cycle are required.

For every CO₂ molecule entering the Calvin cycle, 3 molecules of ATP and 2 of NADPH are required. To make one glucose molecule we need 18 ATP and 12 NADPH.