The iOS 18 Calculator on iPhone now allows for easy currency and unit conversion without the need for a separate app.
To convert currency or units, open the Calculator app and tap on Basic or Scientific. Then toggle Convert to the right and select the conversion category such as currency, length, weight, etc.
Choose the conversion options for both 'from' and 'to' fields and enter the amount. The conversion will be displayed instantly.
This feature is available on iPhone XR and later models running iOS 18 or later.