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. Every round trip costs money on both legs — converting EUR→USD, then USD→EUR when you change plans, then EUR→USD again, burns the spread three times before a single return is earned. 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. Note: currency-hedged versions don't solve this — they replace conversion drag with rolling hedge costs that can be higher.
Real-world FX workflows compared
The calculator models the cost of a single workflow. Which workflow you choose — and whether you switch between them — matters just as much as the per-conversion rate. Here's how the six main approaches compare in practice.
| Workflow | How it works | Hidden issue | Best for |
|---|---|---|---|
| Auto FX on every buy | Broker converts EUR→USD automatically at the point of each purchase | Repeated spread on every transaction — invisible in account statements | Convenience buyers; small portfolios where simplicity outweighs cost |
| Manual monthly conversion | Convert once per month in your broker's FX screen, then buy from the currency balance | Still repeated, but controllable — one conversion covers all buys that month | Regular investors who want to reduce churn without full multi-currency complexity |
| Quarterly batch conversion | Convert every 3 months in a larger lump; hold the balance and draw from it | Requires staging cash ahead of purchases — small window of cash drag between contribution and conversion | Mid-size portfolios; brokers with fixed FX fees that reward larger amounts |
| EUR-listed UCITS ETFs | Buy EUR-priced shares of UCITS funds; no per-trade FX conversion required | Underlying USD/global exposure remains unchanged — only the trading currency changes | Simplicity-first investors; EUR-base accounts; the cleanest entry for beginners |
| Multi-currency cash balance | Hold a USD balance; convert deliberately at low cost once; buy from it over many months | Operational complexity; idle cash drag if the balance sits too long before deployment | Advanced investors; IBKR users; highest efficiency at scale |
| Dividend reinvestment | USD dividends from US holdings are paid in USD, then auto-converted back to EUR in EUR-base accounts | Each dividend triggers a small conversion — individually minor, cumulatively significant for income portfolios over decades | Less critical for UCITS accumulation ETFs; most relevant if holding individual US stocks |
Switching brokers or tickers mid-journey means converting EUR→USD, then later USD→EUR, then EUR→USD again at the new setup. At 0.25% per leg, three round trips consume 1.5% of capital before a single return is earned. Plan once; switch only when the projected saving clearly exceeds the total switching cost including conversion drag.
Currency-hedged ETFs remove exchange rate volatility but introduce a different ongoing cost: rolling forward contracts priced on interest rate differentials. When US rates exceed EUR rates — as they did for much of 2022–2025 — hedging EUR/USD exposure has cost EUR-based investors roughly 1–2% per year embedded in the ETF's total return. For most long-term investors, an unhedged EUR-listed UCITS ETF at a low-spread broker is considerably cheaper.
How to check your broker's real FX fee
Your broker's published FX rate and the rate you actually get are often two different things. Here's how to benchmark what you're really paying in under five minutes — and what the result means.
Open Google (search "EUR USD"), XE.com, Bloomberg, or TradingView and note the mid-market rate at the exact moment you are about to convert. This is the true interbank rate — the neutral benchmark before any markup is applied.
Go to your broker's FX or currency conversion screen. Note the quoted rate before confirming — do not proceed to a market order without recording it first. Most platforms show an indicative rate before execution; use this for a like-for-like comparison.
Subtract your broker's quoted rate from the mid-market rate. Divide by the mid-market rate and multiply by 100. Example: mid-market 1.0850, broker quotes 1.0820 → (1.0850 − 1.0820) ÷ 1.0850 × 100 = 0.28% markup. Enter that number into the calculator above as your FX markup percentage.
Spreads fluctuate with volatility and session timing. One reading can be misleading. Repeat on a separate weekday during normal trading hours and average the two for a more representative figure. Avoid testing on Fridays after 4 PM CET, weekends, or immediately after major data releases (NFP, CPI, ECB decisions) when spreads are temporarily wider.
| Broker type | Typical FX markup | Signal |
|---|---|---|
| Retail bank / traditional broker | 0.5% – 2.0% | High — optimise immediately |
| Neobroker (Trade Republic, Scalable, etc.) | 0.15% – 0.35% | Moderate — material at scale |
| DEGIRO, Saxo | 0.10% – 0.25% | Moderate |
| Interactive Brokers (IBKR) | ~0.03% | Near mid-market — best available for retail |
| Revolut / Wise (off-peak) | 0.35% – 1.0%+ | Watch weekend markups — can spike sharply above their weekday rate |
Trading currency ≠ currency exposure
This is the single most misunderstood concept among European ETF investors. The currency your ETF trades in has almost nothing to do with the currency risk inside it — and confusing the two leads to both over-optimisation and under-optimisation of FX costs.
| ETF listing | Trading currency | Underlying exposure | FX drag present? |
|---|---|---|---|
| EUR-listed S&P 500 UCITS ETF (e.g. CSPX on Xetra) | EUR | ~100% USD (US equities priced in USD) | No per-trade conversion drag |
| GBP-listed MSCI World UCITS ETF | GBP | ~65% USD, diversified global | Conversion drag if your account is EUR-base |
| USD-listed S&P 500 ETF (e.g. SPY on NYSE) | USD | USD | Full conversion drag — EUR→USD on every purchase |
| EUR-hedged MSCI World ETF (e.g. IWDE) | EUR | Global exposure — hedged back to EUR via derivatives | No conversion drag — but ongoing rolling hedge cost applies instead |
| EUR-listed emerging markets UCITS ETF | EUR | Mixed: CNY, INR, BRL, KRW, and others | No per-trade conversion — multi-currency exposure carried inside the fund |
Buying an EUR-listed UCITS ETF from a EUR-base account eliminates conversion drag on each purchase entirely. You are not paying an FX markup every time you invest. The underlying assets still move with EUR/USD rates — that's currency risk, not drag — but your transactions stay in euros throughout.
If USD strengthens against EUR, your EUR-listed S&P 500 ETF goes up in EUR terms. If USD weakens, it goes down — independently of your purchase currency. The EUR listing is a transactional convenience wrapper; the underlying portfolio is still priced in dollars. You have eliminated drag, not risk. These are two different things.
When does FX optimisation actually matter?
The right level of effort depends on contribution size. Over-optimising a small portfolio can cost more time than it saves in fees. Under-optimising a large one leaves real compounding on the table.
At €150/month with a 0.25% spread, the annual FX cost is roughly €4.50 — less than the effort required to switch brokers. Fixed fees dominate at this scale: a €2 flat fee on a €50 conversion is 4%.
At €1,000/month, switching from a 0.25% neobroker to a 0.03% IBKR workflow saves roughly €26/year in nominal fees — and around double that in lost compounding over a 20-year horizon. The setup effort pays for itself within months.
At €5,000 per quarterly conversion, the difference between 0.25% and 0.03% is €11 per conversion, €44/year nominal — but at 7% over 20 years, the future value of that leakage compounds to over €170. Even 0.10% differences are real money.
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.
Why are FX rates worse on weekends?
FX markets effectively close on Friday evening and reopen Sunday evening. Brokers that still allow conversions during this window have to price in the risk of gap moves when markets reopen Monday, and they compensate by widening spreads significantly. Some platforms have historically charged markups on weekends that are two to three times their standard weekday rate. For any meaningful conversion, execute during core weekday market hours — Monday to Thursday, roughly 9 AM to 5 PM CET — when liquidity is highest and spreads are tightest.
Does buying a currency-hedged ETF eliminate FX drag?
It eliminates transaction-level conversion drag but introduces a different ongoing cost. Currency-hedged ETFs use rolling forward contracts to offset exchange rate movements, and the price of that hedge is set by interest rate differentials between currencies. When US rates exceed EUR rates — as they did for much of 2022–2025 — hedging EUR/USD exposure has cost EUR-based investors roughly 1–2% per year embedded in the ETF's total return. For most long-term investors buying EUR-listed UCITS ETFs at a low-markup broker, the unhedged version is considerably cheaper overall.
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.