Methodology
How the Calculators Work
Every Maker Profitability calculator has a written specification and deterministic formulas. The same valid inputs produce the same numerical results.
Defined formulas and assumptions
Each tool defines its inputs, formulas, validation, rounding, scope, and exclusions before presenting a result. Formula details differ because product pricing, marketplace fees, events, wholesale orders, custom work, and capacity answer different business questions.
Money and rounding
Where established for a calculator, currency values are converted to integer cents for calculation. Percentage precision and rounding direction are defined per tool, including when a minimum price or order quantity must round upward.
Deliberate validation
Inputs are checked for required values, supported formats, sensible boundaries, and combinations that would make a formula impossible. Invalid entries do not silently become valid assumptions.
Automated testing
Automated calculation and regression testing runs throughout the project. Tests cover formula examples, edge cases, validation, rounding, interfaces, and protections against accidental changes.
Use the estimate as a starting point
Results depend on the numbers you enter. Use your actual costs, time, prices, and fee assumptions, and read the assumptions and exclusions on the individual calculator page. Marketplace rules and fees can change, so check marketplace-specific assumptions against current information from the provider.
These calculators support planning; they do not predict demand or replace accounting, tax, legal, or financial advice.