From dad's Excel sheet to a website

My dad often sent me Excel files, breaking down the costs of his current car and comparing them to several alternatives he had in mind. While the initial Excel template was simple, he expanded it over the years by adding various metrics. For instance, when changes in the tax structure for diesel cars—considering both the annual vehicle tax and fuel tax—were anticipated, he ensured the Excel sheet was equipped with all pertinent fields. He'd then adjust these parameters based on emerging developments to evaluate the cost-effectiveness of retaining his current car versus switching to a new one.

This detailed methodology empowered him to discern if a different car model might present a more economical option. At first, I wondered if he used this strategy merely to rationalize potential new car acquisitions. However, the number of times he deemed his existing car as the optimal choice dispelled that notion.

Above is a summary section of my dad's comparison from 2020 (in Finnish). It contrasts his current car (both with and without the diesel tax, and factoring in an increased price of diesel) with a natural gas-powered Skoda Octavia and a plug-in hybrid Toyota Corolla.

It was around Thanksgiving 2021 when I began building a website based on the Excel sheet. I managed to get calculator feature completed during the holidays. However, since it was hosted without a backend, sharing the car comparisons was virtually impossible. As I started working on the backend, other obligations arose, preventing me from dedicating time to the project for an extended period.

After my dad passed in August 2023, I decided to finish the work and publish the website. Unfortunately, I no longer have my most enthusiastic user to provide me feedback, but hopefully there are other car and cost enthusiasts out there!

Dad, here is the first revision.