Last updated: August 5, 2026
This app is built for people who live between two measurement systems - miles and kilometers, pounds and kilograms, Fahrenheit and Celsius, dollars and everything else. Open it, type, get the answer. No ads, no accounts, no tracking.
Everyday units, not a physics textbook
Length, weight, temperature, volume, area, speed, time, data and more — with the units people actually use in each country.
Currency from the European Central Bank
Rates are fetched from frankfurter.dev, an open source ECB feed, and cached so the last rates stay available offline.
A calculator that remembers
Do the maths without leaving the app. Your last 30 calculations stay in history.
Recents and favorites
The conversions you repeat are one tap away. Star the ones you use every day.
Works offline
Everything except live currency rates runs with no network at all.
Nothing is collected
No analytics, no crash SDKs, no ads, no account. Your settings and history never leave your device.
Something not working, or a unit missing?
Write to me directly - the app is made by one person, and every email is read.
Replies usually go out within two business days.
To speed things up, include: your device (for example iPhone 14, iOS 18.4), the app version from Settings, and what you did right before the problem appeared.
My currency rates look out of date
Rates come from the European Central Bank and are published once per business day, around 16:00 CET. There are no updates on weekends or ECB holidays, so a Saturday rate is Friday's rate. Open the currency screen while online to refresh; if it still fails, check that the app is allowed to use mobile data.
Does the app work without internet?
Yes, apart from live currency rates. All other conversions and the calculator are fully offline. The last downloaded exchange rates stay cached, so currency keeps working with the previous day's numbers.
Is there a subscription?
No. Instant Converter is a one-time purchase for the full app. There are no in-app purchases, ads, or paid tiers.
I bought it on my iPhone. Do I pay again on my iPad or Mac?
No, as long as you use the same Apple Account. Install from the App Store and the purchase is recognised automatically. Google Play and the App Store are separate stores, so an Android purchase does not carry over to iOS.
How do I get a refund?
Refunds are handled by Apple, not by me. Go to reportaproblem.apple.com, sign in with your Apple Account and choose the purchase. If the app is not doing what you expected, email me first — most problems have a fix.
A unit or currency I need is missing
Send me the unit, the category it belongs in, and the country where it is used. Requests from real users are how the list grows.
What data does the app store?
Only on your device: theme and keyboard preferences, your last 10 conversions, favourites, the last 30 calculations, and the cached exchange rates. Nothing is uploaded, synced or shared. Details are in the Privacy Policy.
How do I delete my data?
Delete the app, or clear its data in your device settings. Everything is local, so that removes all of it.