How to calculate exchange rates manually

6 October 2026 · Calcosmo editorial team

At the ECB reference rate of 5 October 2026 (1 euro = 1.1204 dollars), 100 euros is about $112.04 and 100 dollars is about €89.25. Rates change every day; find the current rate in the currency converter.

Euro and dollar conversion table

Based on the ECB rate of 5 October 2026:

How to calculate it yourself

The ECB publishes rates as “1 euro = X dollars”. To convert:

• Euros to dollars: amount in euros × rate. €100 × 1.1204 = $112.04.
• Dollars to euros: amount in dollars ÷ rate. $100 ÷ 1.1204 = €89.25.

A quick mental shortcut: at a rate around 1.12, add about 12% to a euro amount to get dollars, or take off about 10% from a dollar amount to get euros.

Direct and inverse rates

Every exchange rate can be written two ways. If 1 euro = 1.1204 dollars (the direct rate for EUR/USD), then 1 dollar = 1 ÷ 1.1204 = 0.8925 euros (the inverse rate). Check which way a rate is quoted before you multiply or divide: the currency mentioned first is the one you hold 1 unit of.

Cross rates

To convert between two currencies that are both quoted against the euro, go via the euro. With 1 euro = 1.1204 dollars and 1 euro = 0.8472 pounds, one pound is 1.1204 ÷ 0.8472 = 1.3225 dollars. So £100 is about $132.25.

Spotting a hidden markup

Compare the rate you are offered with the mid-market rate. If an exchange desk sells you dollars at 1.0650 per euro while the mid-market rate is 1.1204, you receive (1.1204 − 1.0650) ÷ 1.1204 = 4.9% less than the fair rate. That margin is the real cost of the exchange, even if the desk advertises “0% commission”.

Why does your bank give you less?

The ECB rate is a mid-market rate: exactly halfway between the buy and sell price. When you actually exchange money or pay by card, the provider adds a margin:

• Debit and credit cards abroad: many banks charge a foreign transaction fee of 1% to 3%.
• Airport exchange desks: the gap with the mid-market rate can be 5% or more.
• Dynamic currency conversion: paying in your home currency at a foreign terminal often costs 3% to 7% extra.

Read how to keep these costs down in paying by card abroad: which exchange rate do you get?.

Other currencies

The currency converter also converts British pounds, Swiss francs, Japanese yen and more than twenty other currencies. On 5 October 2026, 100 British pounds was worth about $132.25.