Swap / Rollover Calculator

Estimated overnight financing from interest-rate differential. Educational — your broker's actual swap will differ.

Rate differential

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Per-day swap (in quote ccy)

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Total swap (in account ccy)

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How swap is estimated

Swap (also called rollover) is the financing applied to a position held past the daily close. The textbook approximation:

swap_per_day = notional × (rate_long_ccy − rate_short_ccy) ÷ 360

Going long a pair, you earn interest on the base currency and pay on the quote; going short, the sign flips.

This is an estimate. Real broker swaps include a markup, broker-specific funding rates, and sometimes triple-swap on Wednesdays (covering the weekend). Always check your broker's swap table before holding overnight.

Useful reference rates: USD ≈ Fed Funds, EUR ≈ ESTR, GBP ≈ SONIA, JPY ≈ TONA.