Most trading fee calculators show you two numbers: the dollar amount and the percentage of notional. Both are correct. Neither is useful. Here's the problem. Dollar-denominated fees hide the real cost Say you're trading Bitcoin perpetuals on Bybit. Taker fee is 0.055% each side. You buy $10,000 notional. Entry fee: $5.50 Exit fee: $5.50 Round trip: $11.00 Does that matter? Impossible to say without knowing one more number: how much are you risking on this trade? If your stop is $200 away (2% of position), your risk is $200. The $11 fee is 5.5% of your risk. That's 0.055R — acceptable for most strategies. If your stop is $50 away (0.5%), your risk is $50. The $11 fee is 22% of your risk. That's 0.22R. On a 1:2 trade, your effective R:R just became roughly 1:1.56. At 100 trades, you've given up 22R to the exchange. Same fee, same position size, completely different impact depending on your actual risk. What R multiples expose The R multiple framework comes from Van Tharp's work on expectancy.…