Convert units and currencies faster than you type. Here is how:

The number
Begin by entering the number you want to convert

Type here, no need to switch keyboards

Instant result
The units from previous conversions are used


The unit
Next, enter the first letter of the unit, say, g

All units starting with g appear, no matter the category

Auto target
Most probable target unit is used based on your history

Inline results
Most probable convertions are done for each suggestion


Go to the history
Clear the unit with backspace

The history
Previously used units


Go to the menu
Tap here to see the all available units

Results, results, results
Even here, you see all the results before you tap

Going back
Tap the value to change it, tap the unit or swipe from the left edge of the screen to get back to history


Keyboard still here
Get back to typing any moment

Currency rates updated
The approximate result is shown while updating


Go to the target unit
Tap the target unit above, press space or Next on the keyboard, or just swipe from the right edge

Copy result
Tap the result, then select Copy

Swap the values
Tap the = sign


Start over
Convert something else


Convert clipboard
Ångström picks up the number and the unit from clipboard on opening.

Use history
Tap space or Next when entering the number to get to the history.

Change sign
Long tap . to change the sign of the number, i. e. to convert −15 °C.

Swipe right and left
To move between the number, source and target units, swipe from the edges.

Tap the mic button if available and say “5 pounds in dollars”.

“Simple and effective”
the first App Store review we got


We have started from scratch. You have a number in your head, you want it converted stat. You do not want an endless list of categories distracting you.

We ask you for a number and strive to give you the answer with as little taps as possible. Ideally, with zero taps. That is why we check out your clipboard first. We use the units from the previous convertion before you change them. We show you your unit history before you have started typing the unit. We try to guess the target unit i. e. we know that it is natural to convert feet to meters, but miles to kilometers. We learn what you convert to make better guesses over time. We keep currency rates updated, but show you approximate values when offline. We support alternative spelling of many units.

The menu of categories will not get in your way if you don’t ask for it. But if you are curious, tap the source unit and then “select from list”.

Every screen of the app is as informative as possible. Even in the menu we show you the results of possible convertions with each unit.

Blog posts on the design of Ångström:

No favorites
We focused on the idea of maintaining conversion history and learning the user’s habits.

The update animation
Instead of showing a boring spinner, we have animated our approximate equality sign.

Ångström Style System
Our styling engine for Cocoa uses Dropbox synchronization and shake-to-refresh.


Type 45f, get °F in centigrade, feet in meters and more; the result updates live as you refine your query

Dedicated numpad helps to avoid switching between alphabetical and numeric keyboards

Just press space after entering a number to convert all units from your history at once

We keep currency rates updated in background to remain helpful in a flight or in a subway

You don’t need to think about unit categories to convert things, but what if you are just curious?

“Great idea and nice implementation”
from one of the first App Store reviews

Ilya Birman

Alex Babaev
Author and app developer