The loop
Everything in Sim Companies comes down to one cycle. You own buildings. Buildings turn inputs into outputs over time, paying wages the whole while. You sell the outputs. What is left after inputs and wages is your profit.
That is the whole game. Every decision you will make — what to build, what to produce, whether to buy a material or make it — is a question about which version of that cycle earns the most per hour.
Why "per hour" is the number that matters
Beginners usually compare products by how much profit each unit makes. That is the wrong comparison, and it is expensive.
A building is a machine that runs continuously. What you care about is how much money it makes while it runs, not how much it makes per item. A product that earns $2 a unit but produces 500 an hour beats a product that earns $40 a unit and produces 5.
Whenever this site shows you a profit figure, the per-hour number is the headline for exactly this reason.
Product A: $2.00 profit per unit, 500 units/hour → $1,000/hour Product B: $40.00 profit per unit, 5 units/hour → $200/hour Product A is five times better, despite looking twenty times worse per unit.
Where new players lose money
Almost always in the same place: they count the cost of materials and forget everything else. Wages run whether or not the building is producing something worth selling. Administration overhead multiplies those wages as your company grows. Selling on the Exchange costs a fee. Moving goods costs transport.
A production line that looks profitable on materials alone is routinely loss-making once the rest is counted. Every calculator here counts all of it by default.