financial-precision-math

Prevent floating-point monetary errors by enforcing integer-based storage and arithmetic across all layers. Store currency values as INTEGER or BIGINT representing the smallest units, like cents, to ensure exact money math without precision loss.

Handle currency formatting at the UI level by keeping all backend computations as integer arithmetic and applying locale-aware formatting only at the rendering stage. This approach guarantees exact monetary values are preserved until final display.

Integer arithmetic works effectively for financial workflows like payroll, taxes, and inventory valuation. By converting currencies to their smallest units and using safe integer types, you maintain exact amounts where precision is critical.

Storing money as floating-point numbers causes errors because binary representations cannot exactly represent many decimal fractions. Enforcing integer types like INTEGER or BIGINT in Postgres and TypeScript prevents these inherent precision losses.

You can and should use BIGINT for price calculations to avoid rounding issues. Storing monetary values as integers representing the smallest currency units ensures exact arithmetic across backend services and database schemas.

Convert currencies to cents or their smallest units before any computation or database storage. This integer conversion is required for pricing, tax, and payroll workflows to prevent floating-point monetary errors and maintain exact values.