FX drag calculator:
what currency conversion actually costs you
“Commission-free” doesn’t mean free. FX spreads, markups, and fixed conversion fees compound silently over years. This calculator estimates your real conversion cost — and lets you compare two workflows side by side to see what switching actually saves.
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TL;DR
- Total nominal fees paid on FX conversions over your horizon.
- Lost compounding — the future value of fees that never stayed invested.
- Side-by-side comparison of two different FX workflows.
- Plain-language interpretation of whether the difference is material.
- ETF bid/ask spreads — separate execution cost.
- Broker commissions or platform custody fees.
- Currency risk — this models conversion cost, not price movement.
- Taxes at any level.
Compare two FX workflows
Enter your shared parameters once, set the FX cost per scenario, and see how the difference compounds over your horizon. Use the presets to load real-world benchmarks instantly.
What FX drag actually is
Three components, one silent leak — and none of them appear on your broker's headline fee schedule.
| Component | What it is | Typical range |
|---|---|---|
| FX spread / markup | The gap between mid-market rate and your executed rate | 0.03% (IBKR) → 1.0%+ (banks) |
| Fixed fee / minimum | Flat charge per conversion — hurts small or frequent buyers most | €0 → €5+ |
| FX churn | Repeated conversions from switching brokers, tickers, or plans | Biggest avoidable leak |
| Lost compounding | Every fee is money that never stays invested and grows | Compounds with time horizon |
Every fee paid is money that doesn't stay invested. At €1.25/month in FX fees over 20 years at 7%, that's not €300 lost — it's over €600 in lost compounding on top. The longer the horizon, the heavier the hidden cost.
European investors who buy USD-denominated assets regularly: repeated EUR→USD conversions at a neobroker's default markup (0.15–0.35%) add up to a meaningful annual cost that's rarely visible in a single transaction.
How to reduce FX drag — in order
Most investors focus on TER first. For non-US investors converting currencies regularly, the priority order is usually different.
Don't convert back and forth because you're switching tickers, plans, or brokers. Each round trip costs twice. One setup, left alone, beats endless re-optimising. Decide once and stay.
Deposit in your base currency, convert deliberately at low cost, hold the foreign currency balance, and buy from it. IBKR lets you do this at ~0.03% — one convert covers many purchases without repeated friction.
If your broker charges a flat fee per conversion, consolidate: convert less often in larger amounts rather than small amounts monthly. A €2 fixed fee on a €100 monthly buy is 2% — devastating at scale.
EUR-listed UCITS ETFs on Xetra or Euronext avoid the conversion step on each purchase entirely. You still have underlying USD exposure from the holdings, but you eliminate conversion drag per trade for simpler portfolios.
Want the lowest FX costs available in Europe?
Interactive Brokers charges around 0.03% on FX conversions — roughly 8× cheaper than the average neobroker and 30× cheaper than a typical bank transfer. The setup takes a couple of hours and pays for itself within months at any meaningful contribution level.
Go deeper
Frequently asked questions
Is FX drag the same thing as FX risk?
No. FX risk is exchange rate movement affecting your returns — EUR/USD going up or down changes what your USD assets are worth in euros. FX drag is what you pay to execute the conversion itself: the spread, markup, and fixed fees. You can experience FX drag even if exchange rates never move, and you can minimise drag without taking any view on currency direction.
How do I find my broker's FX markup?
Compare your executed conversion rate to a mid-market reference — Google, XE.com, or Bloomberg — at the same moment. Translate the difference into a percentage. For example, if mid-market is 1.0850 and you get 1.0820, the markup is roughly 0.28%. Repeat on a normal trading day rather than during extreme volatility for a representative reading.
Does conversion frequency matter if the FX cost is just a percentage?
If the cost is purely a percentage and your total contributions are fixed, drag scales roughly linearly with contributions regardless of frequency. Frequency matters most when there are fixed fees or minimums — converting €200 monthly with a €2 fixed fee costs 1% per conversion; converting €2,400 once a year costs only 0.08% of your annual contribution. Frequency also creates cash drag risk if friction makes you delay investing.
If I buy EUR-denominated UCITS ETFs, do I avoid FX drag?
You avoid conversion drag on each purchase because you're buying in your account's base currency. But the underlying currency exposure from the holdings remains unchanged — an EUR-listed MSCI World ETF still holds predominantly USD-priced assets. Separate trading-currency convenience from underlying currency exposure: they are different things, and avoiding conversion drag doesn't mean you have no currency exposure.
What is the biggest avoidable FX mistake?
FX churn: converting back and forth because you keep switching tickers, brokers, or allocation plans. Each round trip costs money on both legs. One clean multi-currency workflow — set up once, left alone for years — almost always beats constant re-optimisation in total cost, even if the per-conversion rate isn't the absolute lowest available.
Should I optimise TER, tracking difference, spreads, or FX first?
For most non-US investors: FX and execution spreads first, then tracking difference, then TER. TER is the visible cost that shows up in fund documents and gets most of the attention. FX and spread leakage are typically the silent drain — at a 0.25% FX markup with monthly contributions over 20 years, the FX cost alone can easily exceed the difference between a 0.07% and 0.20% TER ETF.
QuantRoutine provides educational content only. Nothing on this page is an offer, solicitation, or recommendation to buy or sell any security or to open an account with any specific broker. Investments can lose value, and past performance does not guarantee future results. Calculator results are planning estimates only — actual fees depend on your broker's executed rates, terms, and your specific workflow. Always verify current pricing and eligibility on the broker's official website before making decisions. You are responsible for your own investment, tax, and legal decisions.