How to use this calculator
- Enter units of currency a per base currency, units of currency b per base currency.
- Choose a display currency, then select Calculate. Results also update after a brief pause while you edit.
- Read the result with the assumptions below. Export details or save a second scenario to compare your choices.
Formula and method
B/A=(B/base)/(A/base).
Assumptions and limitations
User-entered same-time quotes; bid/ask spread and transaction fees are not included.
Worked example
With units of currency a per base currency = 4, units of currency b per base currency = 2, units of b per a is approximately 0.5.
What the result means
Derive a cross quote from two rates expressed against the same base.
Common questions
How should I interpret units of b per a?
Derive a cross quote from two rates expressed against the same base.
What should I check before using this result?
User-entered same-time quotes; bid/ask spread and transaction fees are not included.
Methodology and transparency
Calculation specification reviewed on 2026-10-14. Mathematical implementation is tested against independent reference fixtures. This does not imply review by a licensed financial professional. Read the testing and precision policy.