How to use
Enter an amount and the fee rate. The calculator shows the fee and how much is left after it, along with the full working. Add a fixed fee for pricing like "2.9% + 0.30", and a minimum or maximum fee for rules like "0.1%, at least 0.10".
How much should I charge to receive a set amount?
Switch to "Amount to receive" and enter what you need to end up with. Adding the fee on top is not enough, because the fee is charged on the larger amount too. With a 0.6% fee, receiving 1,000.00 takes a charge of 1,006.04, not 1,006.00. The calculator finds the smallest amount that leaves you at least your target.
How is the fee rounded?
The percentage part is rounded to the nearest cent, with halves rounded up, then the fixed fee is added and the minimum and maximum are applied. Calculations use exact decimal arithmetic, so there are no floating-point errors. Your provider may round differently; check its terms for the exact rule.