US Sales-tax-aware Pricing Planner methodology

Recoverable input sales tax: Cₑ = C ÷ (1 + tᵢ) when C is tax-inclusive, otherwise Cₑ = C. Non-recoverable input sales tax: Cₑ = C when C is tax-inclusive, otherwise Cₑ = C × (1 + tᵢ).

Pₑ = Cₑ ÷ (1 − m)

Pᵢ = Pₑ × (1 + tₒ) when registered and displaying an inclusive price; otherwise Pᵢ = Pₑ

T = Pᵢ − Pₑ

G = Pₑ − Cₑ; M = G ÷ Pₑ

Money inputs and outputs use USD. Rates, margins, utilisation and buffers are entered as percentages and converted to decimal values for calculation.

• Target margin must be at least 0% and below 100%; money values must be finite and non-negative.
• A tax-inclusive displayed price divided by (1 + the entered sales tax rate) must round-trip to retained revenue when registration is confirmed.
• Gross profit divided by retained revenue must equal the entered target margin at full engine precision.
• The engine fails closed for unsupported jurisdictions, supply classes and effective periods.
• The engine fails closed until jurisdiction, taxable-sale classification and the rate effective-date check are confirmed; no nationwide threshold is inferred.
• Unknown registration status locks the pricing result; registration decision tools continue to show threshold assessment independently.

• The selected jurisdiction, supply class, effective period, registration and recoverability states are correct.
• All money inputs use one consistent per-unit and inclusive/exclusive basis.
• The current displayed price is a comparison only; it does not change the required price.
• The no-single-national-rate boundary is bound to sba-state-local-sales-tax-us; the combined rate remains a user-confirmed transaction input.

Official dependencies used by this planner are captured in the Margin101 evidence register and version-acknowledged in this page history. User-entered commercial assumptions remain separate from those official inputs.

• The planner does not determine sales tax registration, taxability, place of supply, input-credit eligibility or filing liabilities; it only evaluates the supported confirmed branch.
• It does not determine economic or physical nexus, destination or origin sourcing, local districts, product or customer exemptions, marketplace collection, registration, filing, use tax, holidays, returns or credits.
• Gross profit excludes fixed costs, overhead allocation, financing, income tax and demand response.
• Use the relevant authority guidance or a qualified adviser for the actual transaction.

This is educational decision support, not tax, accounting, legal or financial advice. Check the treatment of your actual transactions under the rules that apply in United States and seek qualified advice where appropriate.

Registered family-level suites test formula invariants and example reconciliation; the release ledger records that coverage without claiming a separate oracle for every line of public copy. Registered official sources block dependent public workflows when their evidence or version acknowledgement is unavailable or invalid. Commercial inputs remain user-supplied because they vary by business and contract.

1. 2026-07-31: Initial public release of the planner and methodology after pre-launch calculation, content, source and interaction review.