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Currency Arbitrage Calculator

Check three cross-rates for a triangular arbitrage deviation — an educational illustration, not a trading tool.

🔒 Runs entirely in your browser — nothing here is ever uploaded

Last reviewed 2026-08-30

About the Currency Arbitrage Calculator

Checks three currency cross-rates for a triangular arbitrage opportunity — whether multiplying them together deviates from 1 — and shows the theoretical profit percentage before any transaction costs, as an educational illustration of the concept.

100% Free Runs in Your Browser No Sign-Up Required
How to use it
  1. Enter three currencies that form a loop and a starting amount.
  2. Enter the three cross-rates connecting them in a cycle.
  3. Read the loop factor and its deviation from 1.
Formula
Loop factor = Rate(A→B) × Rate(B→C) × Rate(C→A). Deviation from parity = (Loop factor − 1) × 100%.
Worked example

USD→EUR = 0.90, EUR→GBP = 0.85, GBP→USD = 1.35, starting with $10,000: loop factor = 1.03275, a +3.275% deviation — the forward loop returns $10,327.50.

Interpreting your result

This is an educational illustration, not a real trading tool. It ignores bid/ask spread, fees, and slippage. Real-world triangular arbitrage opportunities in major currencies are extremely rare and closed within milliseconds by high-frequency trading firms.

Recommendations
  • A deviation under roughly 0.1-0.2% is usually smaller than the combined bid/ask spread and fees you'd actually pay.
  • Real triangular arbitrage is almost always closed by algorithmic trading within milliseconds.
  • This tool is best used to build intuition, not as a signal to attempt real trades.
Frequently asked questions
The theoretical strategy of exploiting a pricing inconsistency across three currency pairs to end up with more of your starting currency than you began with.
Sources
See the full methodology and sources for every finance calculator
Disclaimer

Illustrative estimate only, not financial or tax advice. Verify figures with a licensed adviser or your local tax authority.