Need to know what €500 is in dollars, or how much that US invoice costs in pounds? A currency converter is one of those tools you reach for constantly — for travel, freelancing, e-commerce, and international invoices. This guide covers how conversion works, where the hidden costs hide, and how to get the real rate in 2026.
How currency conversion actually works
Every currency pair has a mid-market rate — the wholesale rate banks trade at. When you convert an amount, the math is simple multiplication:
amount × exchange rate = converted amount
Example: EUR → USD at 1.08 means 500 × 1.08 = $540. The catch is never the math — it's the spread. Banks, airport kiosks, and payment processors mark up the mid-market rate by 1–5% and call it "no fees." Always compare the rate you're offered against the live mid-market rate.
Popular pairs at a glance (indicative, 2026)
| Pair | Direction to remember | Typical range |
|---|---|---|
| EUR → USD | Multiply EUR by ~1.05–1.15 | €1 ≈ $1.05–1.15 |
| GBP → USD | Multiply GBP by ~1.25–1.35 | £1 ≈ $1.25–1.35 |
| USD → EUR | Divide USD by the EUR rate | $1 ≈ €0.87–0.95 |
| GBP → EUR | Multiply GBP by ~1.15–1.20 | £1 ≈ €1.15–1.20 |
Rates move every second, so treat any table as a starting point — check the live rate at the moment you transact. For quick unit-style conversions of any kind, the free unit converter on Tooly also covers length, weight, temperature, and more.
Where the hidden fees are
- Bank and card spreads: 1–3% above mid-market, often invisible because the rate "looks close."
- Airport and hotel kiosks: the worst rates in the world, frequently 8–12% off.
- PayPal / payment processors: ~3–4% plus a fixed fee on top of their spread.
- Dynamic currency conversion (DCC): when a terminal offers to charge you "in your home currency" — this is almost always a worse rate. Always choose local currency.
Rule of thumb: if someone offers to convert "for free," the cost is inside the rate. Ask what the mid-market rate is, then compare.
How to convert currency without getting ripped off
- Look up the live mid-market rate for your pair.
- Multiply your amount by that rate — that's your fair-value reference number.
- Check the rate your bank, card, or service actually offers.
- If the offered rate is more than ~1% worse, use a service with lower spread or pay in local currency.
For freelancers invoicing international clients, this matters on every single payment. Pair a good conversion check with a clean InvoiceForge invoice (with the currency set correctly) and you'll stop leaking money on FX alone.
Use the free converter
Tooly's unit & currency converter runs entirely in your browser — no signup, no tracking, and it handles 160+ currencies alongside everyday unit conversions. For the finance side of your business, BankToCSV converts bank statement PDFs to CSV, and InvoiceForge handles international invoicing.