FX Option Calculator (Garman-Kohlhagen)
Currency option pricing with separate domestic and foreign interest rates — the interbank FX-desk model.
Formula
FX options discount the foreign leg at the foreign rate — holding foreign currency earns r_f, exactly like a dividend yield. The rd−rf differential drives the forward and hence which side of the smile trades rich (carry currencies skew toward depreciation protection).
Not financial advice — for informational and analytical use only. Verify all figures with a qualified professional before acting on them.
Disclaimer: This tool is for general informational and estimation purposes only and is not professional financial, tax, accounting or legal advice. All figures are estimates — verify with a qualified professional before making decisions. Read the full disclaimer.
Need fx option calculator results fast? Analysts, founders, traders and finance professionals use the FX Option Calculator to skip the spreadsheet and get a defensible answer in one step — free, private and instant.
About FX Option Calculator (Garman-Kohlhagen)
Currency option pricing with separate domestic and foreign interest rates — the interbank FX-desk model. FX options discount the foreign leg at the foreign rate — holding foreign currency earns r_f, exactly like a dividend yield. The rd−rf differential drives the forward and hence which side of the smile trades rich (carry currencies skew toward depreciation protection). The governing relationship is C = S·e^(−r_f T)·N(d₁) − K·e^(−r_d T)·N(d₂). The FX Option Calculator computes entirely in your browser — free, private (your figures never leave your device) and instant, recalculating live as you change any input.
How to use FX Option Calculator (Garman-Kohlhagen)
- 1Enter FX spot rate, Strike, Volatility (%), Domestic rate (quote ccy) (%), Foreign rate (base ccy) (%), Days to expiry into the FX Option Calculator.
- 2The result is computed automatically using C = S·e^(−r_f T)·N(d₁) − K·e^(−r_d T)·N(d₂) — there is no button to press.
- 3Change any input to model a different scenario, then copy or share the result.
Why use FX Option Calculator (Garman-Kohlhagen)?
- ✓Computes fx option calculator instantly with the correct formula — no spreadsheet needed
- ✓100% free and unlimited, with no sign-up, login or paywall
- ✓Runs entirely in your browser, so the figures you enter stay private
- ✓Shows the formula, a live worked example and references so you can defend the number
Frequently asked questions
What is the formula behind the FX Option Calculator?+
FX Option Calculator uses C = S·e^(−r_f T)·N(d₁) − K·e^(−r_d T)·N(d₂). FX options discount the foreign leg at the foreign rate — holding foreign currency earns r_f, exactly like a dividend yield. The tool substitutes your actual inputs into this relationship and shows the worked example step by step.
What inputs does the FX Option Calculator need?+
Enter FX spot rate, Strike, Volatility (%), Domestic rate (quote ccy) (%), Foreign rate (base ccy) (%), Days to expiry and the result updates immediately — there is no button to press. Change any value to model a different scenario in real time.
Is the FX Option Calculator free, and is my data private?+
Yes — it is completely free with no sign-up or usage limit, and it runs entirely in your browser, so the numbers you enter are never uploaded or stored on any server. It is for informational and analytical use, not financial advice.
What should I watch out for when using the FX Option Calculator?+
The rd−rf differential drives the forward and hence which side of the smile trades rich (carry currencies skew toward depreciation protection).
What is the FX Option Calculator based on?+
The method follows authoritative sources: Garman & Kohlhagen (1983), JIMF. The formula and references are shown on the page so you can verify and cite the result.
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