Business Startup Financial Decision Modeling

How this engine works

You enter your own figures; the engine models two scenarios side by side and shows the twelve-month difference between them. The outputs are estimates built from your inputs and documented assumptions — not predictions, and not advice. Mood and stress are self-reported context that adjust the wording of the summary, nothing else. Inputs are processed in your browser. The full methodology, including what the engine does not claim, is on the Decision Center.

Step 2: Decision Forge — compare assumptions

Decision scenarios with reflection prompts

Each scenario in the tool above presents two options drawn from this event and models them side by side from the figures you entered. Before the comparison, the page names a cognitive-bias concept as an educational reflection prompt. It is a general prompt attached to the scenario rather than a finding about you: the page does not test whether the concept applies to your situation, and it does not indicate which option you should choose.

Self-reported context at decision time

The page does not create a psychological profile. Mood and stress may tailor wording and general next-step suggestions. They do not change the entered financial values or scenario math. They do not establish decision readiness. The named bias concept is a general reflection prompt; the page does not detect bias, assess decision capacity, diagnose a condition, or predict outcomes.

What the survival data actually says

Almost every page written about starting a business opens with a failure statistic, and almost all of them use a number with no federal source behind it. The measured figures are published by the Bureau of Labor Statistics in its Business Employment Dynamics series, which tracks private-sector establishments from the quarter they open.

Roughly four in five survive the first year, about half reach five years, and about a third reach ten (BLS Business Employment Dynamics, data as of March 2025). The widely repeated claim that nine in ten businesses fail is not supported by any of it.

Two caveats cut in opposite directions and both matter for your own decision. The unit counted is the establishment, not the firm — a single business with three locations appears three times. And a closure is not the same thing as a failure: a profitable business that is sold, merged, relocated across a state line or simply wound up because the owner retired counts as a death in this series exactly like an insolvency. So the survival rate understates how often the owner did perfectly well. Against that, BLS waits three quarters before confirming a death, which excludes temporary shutdowns but also means the most recent quarters are incomplete.

The useful reading is neither doom nor exceptionalism. Plan the downside as “about half of businesses like this are no longer operating in five years,” give the plan a defined point at which you stop, and size the runway so that reaching that point is a decision rather than a collapse.

The filings that are free, and the ones that no longer exist

A significant industry exists to charge new business owners for paperwork that is either free or not required. The current position:

Start-up costs are not deductible the way most people assume

The common belief is that money spent getting a business going is deductible in the year it is spent. It is not. Section 195 lets you elect to deduct up to $5,000 of start-up expenditures in the first year, and a parallel provision allows up to $5,000 of organizational costs. Everything beyond that is amortized over 180 months — fifteen years.

Two details are routinely reported wrongly. The two $5,000 allowances have two separate $50,000 thresholds, each tested against its own category, so $40,000 of start-up costs plus $40,000 of organizational costs still qualifies for both deductions in full even though the total is $80,000. And the 180-month clock begins in the month the active trade or business begins, not the month the money left your account. Spending heavily before you are actually operating does not create a current deduction; it creates a fifteen-year one.

Entity choice, in the order it actually matters

Most of the entity advice available online argues about tax before liability, which is backwards for a business with no revenue yet.

A single-member LLC is by default a disregarded entity for federal income tax: there is no separate income tax return, and the activity appears on your own Schedule C, E or F. It is still a separate entity for employment and certain excise taxes, and it uses its own EIN. Form 8832 elects corporate classification; for S corporation status Form 2553 alone is sufficient, and the deadline is two months and fifteen days after the start of the tax year.

The S corporation pitch is that splitting your pay between salary and distributions reduces self-employment tax. The constraint is that payments to a shareholder-officer must be treated as wages to the extent they represent reasonable compensation for services actually rendered. There is no sixty-forty rule, no percentage safe harbour, and nothing in the Code or the regulations that sets a ratio — it is a facts-and-circumstances test that has been litigated repeatedly (Watson v. United States, 668 F.3d 1008). Any adviser quoting you a split as if it were a rule is quoting folklore.

The liability protection that motivates most formations is real but conditional. It depends on the entity being maintained as genuinely separate: its own bank account, its own records, no casual movement of money between it and you. Commingling is what actually costs people the protection they paid to create.

The tax numbers that govern the first year

Two federal pages are currently stale on exactly these figures, which is a problem when the instinct is to check the government source. The IRS self-employment tax page has been displaying a 2024 wage base, and the newsroom summary of the qualified business income deduction still describes it as applying only to tax years ending on or before 31 December 2025 — which the 2025 legislation superseded. Publication 334, Revenue Procedure 2025-32 and the SSA contribution base page carry the current numbers.

Where the money comes from, and what the SBA actually does

The Small Business Administration does not make 7(a) loans. It guarantees loans made by banks, credit unions and other lenders, and the borrower deals with the lender throughout. The same pattern holds for the other programmes: 504 loans are made through Certified Development Companies, and microloans through non-profit intermediaries. The genuine exception is disaster lending, which the SBA does make directly.

One thing to be clear-eyed about before the entity choice feels like protection: a new business with no trading history will almost always be asked for a personal guarantee. An LLC does not shield you from a debt you personally guaranteed, and the guarantee usually survives the business. That is the single largest gap between what people expect from forming an entity and what it delivers.