In financial modeling, calculating fixed costs and variable costs involves identifying the costs that remain constant regardless of production or sales volume (fixed costs) and those that vary with production or sales volume (variable costs). Here's how you can calculate them:

Identify Fixed Costs:

Fixed costs are expenses that do not change with the level of production or sales. They remain constant within a certain range of activity.
Examples of fixed costs include rent, salaries of permanent staff, insurance premiums, depreciation, and property taxes.
To calculate fixed costs, review the company's financial statements and identify expenses that are consistent over time and not directly tied to production or sales volume.
Calculate Variable Costs:

Variable costs are expenses that change in proportion to the level of production or sales. As production increases, variable costs also increase, and vice versa.
Examples of variable costs include raw materials, direct labor, sales commissions, packaging costs, and shipping expenses.
To calculate variable costs, you can use historical data to determine the variable cost per unit or the variable cost as a percentage of sales revenue.
Segregate Mixed Costs:

Some costs may have elements of both fixed and variable components, known as mixed costs.
To segregate mixed costs into their fixed and variable components, you can use techniques like the high-low method, scattergraph method, or regression analysis.
The high-low method involves selecting the highest and lowest activity levels and corresponding costs and then calculating the variable cost per unit and the total fixed cost.
Build a Financial Model:

Incorporate the calculated fixed costs and variable costs into your financial model.
Use formulas or functions in spreadsheet software to represent fixed costs and variable costs in your model.
For example, you can use the SUM function to aggregate fixed costs, while multiplying the variable cost per unit by the level of activity (e.g., units sold) to calculate variable costs.
Sensitivity Analysis:

Conduct sensitivity analysis to assess the impact of changes in production or sales volume on total costs.
By varying the assumptions related to fixed costs and variable costs, you can analyze how different scenarios affect the company's profitability and financial performance.
By accurately calculating fixed costs and variable costs in your financial model, you can better understand cost structures, conduct scenario analysis, and make informed decisions regarding pricing, production levels, and resource allocation.