Cost accounting
Fixed vs Variable Costs: Examples, Formula, and How They Affect Profit
Every business cost falls into one of two buckets: fixed or variable. The split between them determines your break-even point, your pricing strategy, and how profit scales as you grow. Here's how to classify your expenses and what the mix means for your bottom line.
What Are Fixed Costs?
Fixed costs stay the same regardless of how much you produce or sell. Whether you make one sale or one thousand, these bills arrive at the same amount. Fixed costs are sometimes called overhead or operating expenses in financial statements.
| Expense | Typical Annual Cost | Why It's Fixed |
|---|---|---|
| Rent / Lease | $12,000–$60,000 | Contractual, does not vary with sales volume |
| Salaried Employees | $40,000–$120,000 per employee | Pay is not tied to output in the short term |
| Insurance (GL, workers' comp) | $500–$5,000/year | Policy premiums are set annually |
| Equipment Lease | $200–$2,000/month | Fixed monthly payment per lease contract |
| Software Subscriptions | $30–$500/month | Subscription-based, same price regardless of usage |
| Property Tax | Varies by location | Based on assessed value, not sales |
Source: SBA Office of Advocacy (2026), IBISWorld operating cost benchmarks.
What Are Variable Costs?
Variable costs change in direct proportion to your production or sales volume. When you sell more, they go up. When you sell less, they go down. These are also called cost of goods sold (COGS) or direct costs when they can be traced to a specific product or service.
| Expense | How It Varies | Example Business |
|---|---|---|
| Raw Materials | Goes up with each unit produced | Bakery: flour, sugar, butter per batch |
| Hourly Labor | More hours needed for more output | Restaurant: extra kitchen staff for busy nights |
| Shipping & Fulfillment | Per-package cost tied to orders | E-commerce: each order ships separately |
| Credit Card Processing Fees | Percentage of each transaction | Retail: 2.6–3.5% of every sale |
| Sales Commissions | Percentage or flat fee per sale | Real estate: 3% commission per closing |
| Packaging / Supplies | Used per unit produced | Manufacturing: boxes, labels, inserts |
Source: IBISWorld industry operating cost data, GAAP cost accounting standards.
Fixed vs Variable: Key Differences
| Dimension | Fixed Costs | Variable Costs |
|---|---|---|
| Behavior with sales | Stay constant | Move proportionally |
| Per-unit cost | Decreases as volume grows | Stays roughly constant per unit |
| Predictability | High — known in advance | Low — depends on demand |
| Control timeline | Hard to change quickly (lease, salary) | Can be cut quickly (reduce orders, hours) |
| Business risk | High fixed = high break-even, high risk if sales drop | High variable = lower margin, less risk in downturns |
| Accounting treatment | Operating expenses (SG&A) on P&L | Cost of Goods Sold (COGS) on P&L |
Why Your Cost Structure Matters
The ratio of fixed to variable costs determines three critical business outcomes:
Break-even volume
Higher fixed costs mean you need more sales just to cover overhead before you start making a profit. Use our break-even calculator to find your minimum sales volume.
Pricing flexibility
Businesses with mostly variable costs can offer discounts more aggressively because every sale still covers its direct costs. High-fixed-cost businesses need to maintain price discipline to cover overhead. See our profit margin calculator to model discount scenarios.
Profit scalability
Once fixed costs are covered, additional revenue flows disproportionately to profit (high operating leverage). This is why software companies can be extremely profitable — their costs are overwhelmingly fixed. Use our target profit calculator to see the sales volume needed for your profit goal.
Cost Structure by Industry
Different business models have dramatically different fixed-to-variable ratios. The table below shows typical cost structures across common small business industries.
| Industry | Typical Fixed % | Typical Variable % | Why |
|---|---|---|---|
| Software / SaaS | 80–90% | 10–20% | Salaries, hosting, subscriptions. Low per-customer delivery cost. |
| Restaurant | 30–40% | 60–70% | Food cost is ~30% of revenue. Labor is part fixed (salaried) and part variable (hourly). |
| Construction | 20–35% | 65–80% | Materials, subcontractors, and equipment rental are project-specific. |
| E-commerce Retail | 15–25% | 75–85% | Cost of goods (inventory), shipping, and payment processing dominate. |
| Consulting / Services | 40–50% | 50–60% | Salaries fixed; contractor/subcontractor costs variable with projects. |
| Manufacturing | 25–40% | 60–75% | Raw materials and direct labor are variable; factory lease and equipment fixed. |
Source: IBISWorld industry financial ratios (2026), SBA Office of Advocacy cost benchmarks. Exact ratios vary by business size and business model.
The Formula for Total Cost
The relationship between fixed costs, variable costs, and volume is captured in the total cost formula used in managerial accounting:
For example, a bakery with $3,000/month in fixed costs (rent, insurance, equipment lease) and $2.50 per unit in variable costs (flour, sugar, packaging) has a total cost of $3,000 + ($2.50 × Q) where Q is the number of units produced. At 1,000 units, total cost = $3,000 + $2,500 = $5,500. At 2,000 units, total cost = $3,000 + $5,000 = $8,000.
This formula is the foundation of break-even analysis, margin calculation, and pricing decisions. See our break-even calculator to apply it to your business numbers.
Calculate Your Cost Structure
Understanding your fixed vs variable split is the first step. These free calculators help you turn that understanding into actionable numbers:
Frequently asked questions
Can a cost be both fixed and variable?+
Some costs have a fixed base and a variable component. These are called semi-variable or mixed costs. For example, a phone plan has a fixed monthly line fee plus variable per-minute charges. A utility bill has a fixed connection charge plus variable usage charges. In break-even analysis, semi-variable costs are usually split into their fixed and variable portions for accurate calculation.
How do fixed and variable costs affect break-even point?+
The break-even point is where total revenue equals total costs (fixed + variable). A business with high fixed costs and low variable costs (like a software company) has a high break-even point but very profitable scaling beyond it. A business with low fixed costs and high variable costs (like a consulting firm) breaks even quickly but has less upside per dollar of revenue. Use our break-even calculator to see how your own cost structure affects your break-even volume.
Are salaries fixed or variable costs?+
Salaried employees are typically fixed costs because their pay doesn't change with production volume. Hourly workers are variable costs because their hours adjust with workload. For some analytical purposes, all labor costs are treated as variable if headcount can be adjusted. In reality most small businesses have a mix: core salaried staff are fixed, seasonal hourly help is variable.
How do I calculate total cost for my business?+
Total cost = Fixed Costs + Variable Costs. To calculate it: (1) list all your expenses for a period (month or year). (2) Classify each as fixed or variable. (3) Sum each category. (4) Add them together. Our profit margin calculator and COGS calculator use this framework to help you understand your true costs per unit or per project.
Does classifying costs as fixed or variable affect my taxes?+
Not directly. The IRS does not require businesses to separate fixed from variable costs on tax returns. The distinction is used for internal management accounting — pricing decisions, break-even analysis, and profitability planning. However, properly understanding your cost structure helps you make better tax-planning decisions, such as timing equipment purchases (fixed) vs. inventory purchases (variable).