Albrecht – the Grade Calculator App

App for iOS helping teachers to distribute fair grades to their students.


One of a teacher's repeating jobs is to correct tests, calculate scores and convert those to grades. The last step is often a pain: A linear scale doesn't help out in most cases which makes it a challenging piece of math to find a fair formula.


What type of help can be provided to teachers to calculate their students' grades? How can a mobile app become a more efficient replacement to the common conversion practices of teachers?


Albrecht offers a straightforward and yet comprehensible method to calculate grades. It's an iOS App I developed together with Raphael Jecker in 2015.

Nowadays teachers don't follow strict linear scales (Rule of Three formula): For example, even if the class performed very badly at a test, the teacher will not want every student to be insufficient. Often it is required by the school to reach a certain grade average. The linear scale doesn't always help out, but not using it can make calculation challenging if you're not a math teacher.


At the heart of Albrecht and at the top of the app's screen is a three-step scale to map the highest and lowest scores to corresponding grades. If however a linear scale doesn't do the work, a bend can be applied by defining a value pair in the middle. Below the app offers a visual allocation and displays the average grade.

In the following video, you can see the app in action – unfortunately it's not available in the App Store anymore.

To promote the app and explain its functionality a dedicated website was created:



1. Research & Concept

Our research told us that teachers often use excel tables containing pre-set formulas and configurable variables to help them with the grade conversion. They rely on those "black boxes" to do their magic, but they don't have much understanding of what's going on behind the surface.

Being a part-time teacher himself, Raphael proposed the method of the three-step scale: It allows the user to enter three value pairs while the one in the middle isn't mandatory. By defining the first and the last value pair the score-to-grade conversion is based on a linear scale. Once augmented by a third pair of values in the middle, a bend in the scale is created. The middle position becomes an interesting manipulation tool for teachers, while letting them know what's happening in terms of calculation.

Based on the three-step scale's configuration, extra information like the average grade and the grade's distribution can be visualized. Once all grade's have been calculated an CSV export option needs to be provided.

2. Design

Keeping things easy was of highest priority, so I insisted on letting everything happen on only one screen: the teacher should use his/her mobile phone and Albrecht as the only tool when correcting tests. Designwise this meant to follow the "one screen concept" known from the basic calculator app from iOS. Going in this direction, we understood that the app needed to have some introduction screens when the user runs it for the first time.

In multiple iterations I started to reduce the design as much as possible:

design evolution

The color selection was important for the interface as it allows the encoding of scores and grades. Once the screen design was defined, I tested out different color schemes:

color evolution

The tool's reduction should also be expressed in the app's icon, so I did several variants (we finally went for the one in the center).

app icon variants

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