Why calculate when the percentage is right there
The percentage shown across the site is the gross price difference. Your actual result depends on things only you know: your fee tier, how many round trips a day you are willing to do, what leverage you use and what a transfer between venues costs you. The calculators take those inputs and give you the answer in money.
P2P route calculator
Enter the starting fiat amount, the buy and sell prices, the fees on both marketplaces and, if any, the cost of moving coins between them. The calculator shows how many coins you end up with, how much money comes back, and the profit in both currency and percent.
One field deserves attention: round trips per day. It converts a single trade into a daily result and is usefully sobering — a route earning a dollar fifty per trip, done three times a day, is under a hundred and fifty a month for constant attention.
Funding calculator
Here you set position size, the rates on the long and short venues, the fee and the holding period. The output shows what each leg earns, what fees take away and the resulting APR.
Its main value is showing at which rate the route turns profitable at all. The fee is deducted four times, and on modest rates it turns out you must hold for several days simply to cover entry and exit.
Spot arbitrage calculator
Capital, buy price, sell price, trading fee and the coin withdrawal fee. That last one is a flat amount, and it is what turns a pretty percentage into zero on small size. The calculator shows how many coins you buy, how many survive the withdrawal, and what the sale brings in.
Percentage difference
The simplest tool: two prices in, the difference in percent both ways out. Handy when you just need to size up a gap without building the whole route.
Using this in practice
Take a route from the P2P or CEX page, move the numbers into the calculator and substitute your real fees rather than the defaults. Then estimate how long one round trip takes. Very often that step reveals the route is not worth the time — and this is the cheapest possible way to find out.