I've just noticed that many people still don't understand fixed costs and variable costs properly, which is really important if you're thinking about doing business because it's the foundation of good financial management.

Let's start with fixed costs. These are costs that do not change regardless of how much you produce or sell. Imagine you rent an office for 50,000 baht per month; you have to pay this amount every month whether you sell any products or not. That’s a fixed cost that you must bear all the time.

The characteristic of fixed costs is that they are independent of the production volume. Whether you produce a lot or a little, they remain the same. Salaries, insurance, loan interest, depreciation of equipment—all of these are fixed costs that must be paid. Their importance lies in helping you plan your finances clearly because you know exactly how much you need to pay.

In contrast, variable costs change according to the production volume. The more you produce, the higher the costs; the less you produce, the lower the costs. Raw materials, direct labor, energy costs, packaging, transportation—all of these increase or decrease depending on production.

The difference between the two is clear. Fixed costs are stable, making planning easier, but variable costs are more flexible and can be reduced if production decreases. Companies that understand both well can set appropriate product prices, plan production efficiently, and control costs better.

When analyzing total costs (fixed costs + variable costs), the picture becomes clearer about how much you are really spending and allows for better decisions on pricing, investment, or business expansion. Good cost management is the key to a truly sustainable business, no matter what kind of business it is.