Which values should you enter?
Choose the executed value and the maker or taker rate that applies to the product. A limit order can execute as taker, and one order can have several fills. If the entered fee rate already reflects the BNB deduction or another benefit, leave Additional confirmed discount at 0 to avoid deducting it twice. Referral cashback doesn't belong here: it is paid later at a share the referrer sets, which can be 0, and it never lowers the fee charged on the fill. Add a separate discount only when your account confirms it applies and it has not already reduced the rate.
The fill multiplier assumes every fill has the same executed value, fee rate and extra discount. If any of those differ, set the count to 1, calculate each fill separately, then add results in the same unit. Do not multiply a whole-order value by its number of partial fills.
Why can the result differ?
Rounding, fee asset, partial fills and changing liquidity role can affect the record. Reconcile the estimate with trade history and the asset statement. This tool excludes spread, slippage, network charges, interest and tax.