What inputs does the Startup Cost Estimator need?

It takes 1 input: items. Outputs returned: totalOneTime, totalRecurringMonthly / totalRecurringAnnual, totalFirstYear, byCategory / itemCount.

Can I verify the Startup Cost Estimator with a worked example?

Yes. With items = [{Legal, legal, 3000, one-time}, {Equipment, equipment, 5000, one-time}, {SaaS tools, software, 1200, recurring}]. the tool returns totalOneTime = $8,000, totalRecurringMonthly = $1,200, totalRecurringAnnual = $14,400, totalFirstYear = $22,400.

Where does the Startup Cost Estimator get its benchmark data?

Reference data is sourced from: US Small Business Administration — Costs to Start a Business (as of 2024).

What can the Startup Cost Estimator not tell me?

Known limitations: Category definitions are editorial, not GAAP. Use the output as a budgeting aid, not an accounting document. No tax credit or grant modelling (e.g., R&D tax credit, SBIR). Adjust inputs downward by any credits you expect to claim.

Methodology: Startup Cost Estimator

1. Scope

Totals one-time pre-launch costs and recurring first-year costs across categories (legal, tooling, infrastructure, marketing, contingency). It does not replace a cash-flow model — pair it with the Monthly Burn Rate Calculator for operating state.

2. Inputs and outputs

Inputs

items array

Each item: name, category, amount, isRecurring (bool), optional recurringMonths. One array — recurring vs one-time is a per-item flag.

Outputs

totalOneTime

Sum of items where isRecurring = false.
totalRecurringMonthly / totalRecurringAnnual

Sum of recurring item amounts, and that × 12.
totalFirstYear

totalOneTime + totalRecurringAnnual (no contingency buffer).
byCategory / itemCount

Per-category one-time/recurring/total, and the item count.

Engine source: src/lib/startup-cost-estimator/engine.ts

3. Formula / scoring logic

one_time_total    = sum(items where !isRecurring)
recurring_monthly = sum(items where isRecurring)
recurring_annual  = recurring_monthly * 12
first_year_total  = one_time_total + recurring_annual

4. Assumptions

There is one items array; each item is flagged one-time or recurring — not two separate lists.
The tool adds NO contingency buffer; build any buffer into the item amounts yourself.
First-year horizon. Payroll is bundled into recurring items by the user — no built-in salary logic.

5. Data sources

US Small Business Administration — Costs to Start a Business as of 2024

6. Known limitations

Category definitions are editorial, not GAAP. Use the output as a budgeting aid, not an accounting document.
No tax credit or grant modelling (e.g., R&D tax credit, SBIR). Adjust inputs downward by any credits you expect to claim.

7. Reproducibility

Input
items = [{Legal, legal, 3000, one-time}, {Equipment, equipment, 5000, one-time}, {SaaS tools, software, 1200, recurring}].

Expected output
totalOneTime = $8,000, totalRecurringMonthly = $1,200, totalRecurringAnnual = $14,400, totalFirstYear = $22,400.

8. Change log

2026-04-24 methodology page first published.

Worked example

Run live against the same engine this site ships (/engines/startup-cost-estimator.js). The inputs and outputs below are recomputed on every build and independently re-verified in CI — they are never hand-authored.

Input

tool: startup_cost_estimator
items[0].name: Legal
items[0].category: legal
items[0].amount: 2000
items[0].is_recurring: false

Output

totalOneTime: 2000
totalRecurringMonthly: 0
totalRecurringAnnual: 0
totalFirstYear: 2000
byCategory.legal.oneTime: 2000
byCategory.legal.recurring: 0
byCategory.legal.total: 2000
itemCount: 1

Frequently asked questions

What does the Startup Cost Estimator calculate?: Totals one-time pre-launch costs and recurring first-year costs across categories (legal, tooling, infrastructure, marketing, contingency). It does not replace a cash-flow model — pair it with the Monthly Burn Rate Calculator for operating state.
What inputs does the Startup Cost Estimator need?: It takes 1 input: items. Outputs returned: totalOneTime, totalRecurringMonthly / totalRecurringAnnual, totalFirstYear, byCategory / itemCount.
What formula does the Startup Cost Estimator use?: The exact computation is: one_time_total = sum(items where !isRecurring); recurring_monthly = sum(items where isRecurring); recurring_annual = recurring_monthly * 12; first_year_total = one_time_total + recurring_annual
Can I verify the Startup Cost Estimator with a worked example?: Yes. With items = [{Legal, legal, 3000, one-time}, {Equipment, equipment, 5000, one-time}, {SaaS tools, software, 1200, recurring}]. the tool returns totalOneTime = $8,000, totalRecurringMonthly = $1,200, totalRecurringAnnual = $14,400, totalFirstYear = $22,400.
Where does the Startup Cost Estimator get its benchmark data?: Reference data is sourced from: US Small Business Administration — Costs to Start a Business (as of 2024).
What can the Startup Cost Estimator not tell me?: Known limitations: Category definitions are editorial, not GAAP. Use the output as a budgeting aid, not an accounting document. No tax credit or grant modelling (e.g., R&D tax credit, SBIR). Adjust inputs downward by any credits you expect to claim.