Below you can find some good info on credit card exchange rates.
https://forum.lowyat.net/topic/1845691Normally I will use Oanda to get the market exchange rate. Both MNCs I work with use Oanda as their go-to place to check the exchange rate, so if it's good enough for them, it's good enough for me.
The exchange rates for your card is not determined by the banks, but by the card network companies (Visa, Mastercard, Amex), and are normally very very similiar to the market rate, almost negligible. You can find the exchange rate for Visa from their website below.
https://usa.visa.com/support/consumer/trave...alculator.html/The banks will then impose a currency conversion fee on your credit card for the foreign transaction, and the rate varies between banks but is generally around 2% to 3% of your transaction price. If I'm not mistaken, debit cards tend to have lower rates of around 1%. This fee is what the 'Bank fee' in the Visa exchange rate calculator is referring to.
Merchant fees for credit card transactions shouldn't really factor into your calculations as they are generally absorbed by most online retailers except for those individual or smaller sellers who are not willing to absorb the cost.
So basically you just use the market rate plus an additional 2% to 3% to calculate how much will be charged to your card. This is also why you can see it states "3% - Typical Credit Card rate" in the 'Interbank' tab when you use the Oanda website.
If compare to money changers, for common currencies like USD, JPY, SGD, THB, they will normally sell you at 1% higher than market rate. They will untung on volume. Harder to find currencies can be significantly more than 1%, cos instead of volume they will untung on margin.
For Paypal, they will ask you if want to charge the credit card linked to your Paypal account in either the foreign currency, or in RM. Rule of thumb is to always select the foreign currency, which means Visa/Mastercard + your bank will do the conversion for you, and rate will be following Visa/Mastercard + bank rate. Basically is same as using your credit card normally, which means the total amount will be market rate + ~3%. If you choose to charge your card in RM, this means Paypal will be doing the conversion process for you, using their own rates and total amount will always end up higher than market rate + 3%. You can google dynamic currency conversion for more info on how this works.
https://en.wikipedia.org/wiki/Dynamic_currency_conversionhttps://thepointsguy.com/2015/06/dynamic-cu...ncy-conversion/