Can I Afford to Start a Business? Startup Runway and Break-Even

Short answer: to see whether you can afford to start a business, add the startup cost, work out the monthly profit you need to cover business costs and your own pay, model how fast sales might grow, and total the shortfall until break-even. With $10,000 of setup, $2,000 of fixed costs, $3,800 of personal costs, a 40% margin and sales growing 15% a month from $3,000, break-even comes in month 13 and the cumulative shortfall is $34,798, so you need about $44,798.

Key takeaways

• The money you need is the setup cost plus the total monthly shortfall until the business covers itself and you.
• Break-even sales = (fixed costs + your pay) ÷ margin. In the example $5,800 ÷ 40% is $14,500 a month.
• Growth speed matters a lot: at 10% a month the need rises to about $59,946, and at 20% it falls to about $37,241 including setup.
• Keep your emergency fund separate, and consider starting part-time to cut the risk.

What do you need to cover each month?

If you start at $3,000 of sales, you are at about 21% of the level you need, so there will be a gap for months. Margin is the profit left from each sale after the direct cost of the product or service. If yours is lower, the sales needed are higher.

How long does the shortfall last?

Assume sales grow 15% a month from $3,000. The gap is $5,800 minus 40% of that month's sales.

Adding up the shortfall for months 1 to 12 gives $34,798. With $10,000 of setup, you need about $44,798 before the business pays for itself and you. Growth of 15% a month for a year is ambitious. Many businesses take longer, so plan on a slower case as well.

How sensitive is it to growth?

Slower growth costs far more, because you pay the gap for longer. Test your own plan at a slower rate than you hope for. If the slow case is out of reach, you can reduce the gap by cutting fixed costs, lowering your own draw, or starting while you keep a job.

How can you reduce the risk?

1. Start part-time while keeping your pay. See how to start a side income without hurting your finances.
2. Prove demand first: pre-sales, a pilot or a few paying customers before major spending.
3. Keep fixed costs low and make costs variable where you can.
4. Hold an emergency fund apart from the business money. See the emergency fund for freelancers.
5. Plan taxes. Self-employment tax adds to your costs. See quarterly estimated taxes.
6. Set a stop-loss: a date or a cash level at which you review or stop.

What else belongs in the decision?

• Health cover, retirement saving and insurance, which an employer no longer provides.
• Personal pledges of your assets or borrowing against your home, which put your own property at risk.
• Your family's needs and tolerance for uncertain income.
• What a good outcome looks like, and what it is worth compared with a salary.

Use the free Goal check to test the savings target, and read can I afford to quit my job for the personal runway.

What mistakes sink new businesses?

Most of these are avoided by a monthly look at cash, a simple separate account and a plan for the slow case.

• Underestimating the time to the first sale, and running out of cash first.
• Paying themselves nothing, then burning out.
• Spending on tools and branding before proving demand.
• Mixing personal and business money, which hides the real numbers.
• Forgetting tax payments, which arrive in lumps.

What does a simple monthly review look like?

• Compare actual sales with your plan.
• Update the shortfall and the months of cash remaining.
• Check fixed costs for anything you can cut.
• Decide on one action for the next month to speed up sales.
• Check the stop-loss. If cash falls below the line, review honestly.

Be honest about the slow case and your appetite for risk. If a business that grows at 10% a month needs about $59,946 and you have $30,000, you can wait, start smaller, or keep your job for longer while the business grows on the side. Starting later with a bigger cushion often beats starting early with too little, because a business that runs out of cash in the first year rarely gets a second chance at the same idea.

Sources and further reading: the IRS has a small business and self-employed tax center, and the Consumer Financial Protection Bureau has guidance on borrowing.

General education, not financial or legal advice. Reviewed October 2026. The model uses made-up costs, margin and growth. Many businesses grow slower than modelled or fail, and no outcome is guaranteed.

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