There is no single 80-gram cup value
A cup describes space, not weight. This page compares the same 80-gram amount across every supported ingredient and keeps the selected ingredient visible beside the result. Honey, oats and flour occupy very different volumes at 80 grams.
Work it out from the reference
Divide 80 by the grams in one cup of your ingredient. For the default flour reference, the calculation is 80 ÷ 120 = 0.6667 US cups. Keep the unrounded result while calculating and round only what you display.
Metric and Australian cups hold 250 ml instead of 236.5882365 ml, so switching the cup system gives a slightly smaller number of cups for the same weight.
Measure the portion you need
A scale can weigh 80 grams directly, which is the most reliable option. If you are using cups, the decimal is an estimate based on the selected reference; the kitchen fraction in the table is marked as approximate whenever it is not exact.