A search for "currency conversion charges" comes down to adding up costs. The price of moving money in and out of a casino is rarely one number. A fee can come from the operator, the payment method or the bank, and a currency conversion can hide inside an exchange rate that looks close to the market one. Putting the parts side by side before the first deposit gives the real cost of every payment.
Operator fees usually attach to withdrawals. Some sites charge a flat amount for each payout, others a percentage, and many waive the fee for one or two withdrawals a month and charge for the rest. A few charge for withdrawing a deposit that was never played through, which is aimed at people using the casino to move money. The fee table in the payment terms lists each case, and it changes more often than anything else in them.
Minimum amounts turn small balances into a cost of their own. A withdrawal minimum above the money left in the account keeps that money in play, and a deposit minimum set higher for some methods pushes players toward a larger first payment. Some casinos also charge an inactivity fee on accounts left untouched for months, which slowly drains a forgotten balance. Both limits are printed on the banking page, usually in a table for each method.
Compare the rate shown on the casino payments page with the rate the bank quotes for the same currencies on the same day.
Wallet, card and crypto charges appear in the method's own price list, not in the casino terms, so that list is the only place to see them beforehand.
A balance below the minimum for the chosen method cannot be withdrawn, so that money stays in play; the minimums are listed by method.
Some casinos charge an inactivity fee on accounts left untouched for months, slowly draining a forgotten balance.