Shares you hold and split factor (e.g. 2 for a 2-for-1 split)—shares after the split. Use 0.5 for 1-for-2 reverse split.
The model multiplies your pre‑split position by a positive split factor: sharesout = sharesin × factor. Shares in must be non‑negative; fractional results are shown with decimals unless the product is (numerically) an integer.
This calculator uses plain decimal numbers. If a result looks wrong, check whether you used a comma instead of a dot (or vice versa) where the field expects one.