Little web tool for product calculations

We are looking to build a little webapp tool for our company which will make some product calculations easier and automatically. Later on it should also have a little "tinder-like" option for products. That would be basic data input mainly. But for now we need a site that has two things: 1) settings in which we can define administrators and normal users (so the site needs a simple login)... and in which we can set some basic values for calculations. 2) a page where a user can make notes and also make a rough product calculation with some input and the values out of the settings. For Both those things i added pictures of how it should roughly be. Looking forward to hear from someone.