A Guide To Variable Costs, Fixed Costs, And Total Costs

If you want to price your products correctly or figure out where your margins are going, you need to understand three numbers: your fixed costs, your variable costs, and how they add up to your total costs. Each one tells you something different about how your business operates — and each one creates different decisions.

This guide explains what each type of cost means, how to calculate them, and how they fit into your broader financial planning. We’ll focus especially on variable costs, since they’re the ones most directly tied to day-to-day output and the ones most businesses underestimate.

What Are Fixed Costs, Variable Costs, And Total Costs?

Understanding the differences between fixed costs, variable costs, and total costs is essential for small business owners seeking to optimize profitability and make informed decisions. Fixed costs are those expenses that remain unchanged regardless of production volume, while variable costs fluctuate with your business activity. Total costs represent the sum of both, directly impacting your bottom line and forming the foundation of effective financial planning and management. Working with a fractional CFO can help small businesses interpret these costs more strategically, offering expert guidance without the commitment of a full-time hire.

Fixed Costs

Fixed costs are recurring expenses that don’t change based on how much you produce or sell. If you rent office space for $2,000 a month, that bill stays the same whether you closed 5 clients or 50.

Common fixed costs include:

• Rent and lease payments
• Salaried employee compensation
• Insurance premiums
• Loan or equipment lease payments
• Software subscriptions with flat monthly fees

Because these costs don’t flex with output, they’re predictable — which makes them useful anchors in budgeting and forecasting.

Variable Costs

Variable costs are expenses that increase or decrease based on your level of business activity. The more you produce or sell, the higher these costs will be.

Common variable costs include:

• Raw materials and direct supplies
• Sales commissions
• Production labor
• Shipping and delivery costs
• Credit card processing fees
• Utilities tied directly to production

Variable costs give you more flexibility than fixed costs during slow periods — when revenue drops, these expenses naturally contract with it. The tradeoff is that they’re harder to predict.

Total Costs

Your total costs are the sum of your fixed and variable costs for a given period. The formula is:

Total Costs = Fixed Costs + Variable Costs

This number sits at the center of most financial planning decisions: it determines your break-even point, informs pricing, and tells you whether a given level of sales is actually profitable.

This figure helps you determine pricing strategies, calculate gross profits, and assess overall financial performance. Without clarity on your total costs, it can be challenging to set the right sales targets or understand your true profitability.

Why the Distinction Matters

Knowing which of your costs are fixed and which are variable changes how you respond to business conditions. A business with mostly fixed costs needs to prioritize volume — it has to sell enough to cover those constant expenses regardless of what happens to revenue. A business with mostly variable costs has more room to adjust when things slow down.

Investors and lenders also look at cost structure when assessing risk. A heavily fixed-cost business is harder to scale back during a downturn; a variable-cost-heavy business can contract more naturally.

Examples Of Variable Costs

Variable costs show up differently depending on your industry and business model. Here are five common types, plus some industry-specific ones worth knowing:

Direct materials

Direct materials are the physical inputs that go into your product. A bakery buys more flour and sugar as it bakes more. A manufacturer orders more components as it builds more units. These costs scale almost perfectly with output, which makes them easy to model once you know your per-unit material cost.

Sales commissions

Commissions are paid only when a sale happens, which makes them one of the cleanest variable costs: the expense exists precisely because revenue was generated. This alignment between cost and income is one reason commissions are a popular compensation structure — they tie cost directly to business activity.

Shipping and delivery

Every order shipped costs money to ship. For e-commerce and distribution businesses, shipping costs can represent a significant portion of variable expenses and are highly sensitive to order volume changes. Carrier rate negotiations and fulfillment efficiency improvements directly reduce this variable cost.

Utilities tied to production

Some utility costs are partly fixed (a base electricity charge) and partly variable (the incremental cost of running more machinery). The variable portion increases during high-production periods and decreases during slow ones. When calculating variable costs, be careful to separate the variable component from the flat base rate — only the portion that changes with activity counts.

Credit card processing fees

Processing fees are charged as a percentage of each transaction, so they scale directly with sales volume. This makes them an easy-to-overlook variable cost for retail and service businesses, especially as ticket sizes grow. A business processing $500K a year at 2.9% is paying nearly $15,000 just in processing fees.

Industry-specific variable costs

Many industries have variable costs specific to their model. A few examples:

• Hospitality: Laundry, guest amenities, and room consumables all increase with occupancy rates.
• Professional services: Subcontractor fees and project-specific tools scale with the number of active engagements.
• SaaS: Cloud hosting costs, usage-based API fees, and payment processing scale with user or transaction volume.
• Healthcare: Medical supplies, disposables, and per-patient staffing costs vary with patient volume.

Identifying all the variable costs in your specific business model is the first step toward an accurate cost structure and more reliable forecasting.

What Is The Difference Between TFC And TVC?

TFC and TVC are the accounting shorthand for the two sides of your cost structure.

Total fixed cost (TFC)

TFC is the sum of all your fixed expenses in a given period — the costs that don’t move regardless of output. Rent, permanent salaries, insurance, and equipment leases all count. Whether you produce zero units or a thousand, TFC stays the same.

One important implication: as you increase output, your fixed cost per unit decreases. If you’re paying $2,000/month in rent and you produce 100 units, your fixed cost per unit is $20. If you produce 1,000 units, it falls to $2. This is the basic principle behind economies of scale.

Total variable cost (TVC)

TVC is the sum of all variable expenses in a period. Unlike TFC, it rises with output. The formula is:

TVC = Variable Cost per Unit × Number of Units Produced

So if each unit costs $1 in materials and labor to produce, and you make 1,000 units, your TVC is $1,000. At 5,000 units, it’s $5,000. The cost per unit stays constant; the total grows with volume.

How TFC and TVC interact

Together, they determine your total cost:

Total Cost (TC) = TFC + TVC

A concrete example: a print shop pays $2,000/month in lease (TFC) and $1 in paper and ink per brochure (TVC). At zero brochures, total cost is $2,000. At 1,000 brochures, it’s $3,000. At 5,000 brochures, it’s $7,000. The lease never changes; the materials cost grows with every job.

Understanding this split lets you model different production scenarios, set pricing that covers both types of costs, and find the output level where margins make the most sense.

How To Calculate Variable Cost From Total Cost And Fixed Cost?

If you know your total costs and your fixed costs for a period, you can isolate your variable costs with a simple subtraction:

Variable Cost = Total Cost – Fixed Cost

This is useful when you want to understand which portion of your spending actually changes with your output, as opposed to what you’re committed to paying regardless.

Step-by-step: how to calculate variable cost

1. Identify total costs for the period. Add up every expense your business incurred — materials, payroll, rent, software, shipping, everything.
2. Identify total fixed costs for the same period. Pull out the costs that stayed flat regardless of output: rent, salaried compensation, insurance, fixed subscriptions.
3. Subtract fixed costs from total costs. The remainder is your total variable cost for that period.

Example

A small business has $120,000 in annual total costs, including $50,000 in fixed costs (rent, insurance, and salaried staff).

Variable Cost = $120,000 – $50,000 = $70,000

That $70,000 covers all expenses that moved with business activity — materials, commissions, shipping, and production utilities.

How to use variable cost in financial planning

Once you know your variable costs, you can:

• Price products accurately by building in a margin above the combined fixed and variable cost per unit
• Run break-even analysis to find the output level where total revenue covers total costs
• Model different production scenarios to understand how revenue changes at different volumes
• Identify cost reduction opportunities by reviewing which variable categories have grown faster than revenue

Variable cost calculations are also an input for gross margin analysis, contribution margin pricing, and budget variance reviews.

Common calculation pitfalls

A few things to watch for:

• Semi-variable costs: Some costs have a fixed component and a variable component — utilities are a common example (flat base charge plus usage). Only count the variable portion in your variable cost calculation.
• Outdated data: Variable costs shift as your business grows, as suppliers change prices, or as you enter new markets. Update your cost breakdowns regularly, not just at year-end.
• Misclassification: A salary is a fixed cost even if you increase hours during busy seasons. A contractor paid per project is a variable cost. Be precise about which category each expense belongs in.

Fixed and variable costs are the two levers every business owner is always pulling, even if they don’t think about them in those terms. The more clearly you can see each one, the easier it becomes to price confidently, plan for growth, and respond when conditions change.

If you’d like help building out a cost structure analysis or integrating these calculations into your monthly reporting, the Milestone team works with small businesses on exactly this kind of financial groundwork.