Fidamen

Business Loan APR Calculator

This calculator helps business borrowers estimate periodic payments, effective APR, total interest, and compare monthly versus bi-weekly payment schedules. It accepts upfront fees and optional recurring extra payments so you can see realistic cost outcomes.

Results are numeric estimates for planning and negotiation; they are not a legally binding disclosure. Use the outputs to compare offers, verify lender disclosures, and estimate cash flow impacts of switching frequency or adding extra payments.

Updated Nov 10, 2025QA PASS — golden 25 / edge 120Run golden-edge-2026-01-23

Governance

Record 06b054d45292 • Reviewed by Fidamen Standards Committee

Calculates periodic payment, total interest, and effective APR for the selected payment frequency (e.g., bi-weekly = 26 payments/year). Includes loan origination fees in total cost.

Inputs

Results

Updates as you type

Payment per period

—

Total interest paid

—

Total amount paid (including fees)

—

Effective APR (annualized)

2400.00%

Estimated number of periods with extra payment

—

OutputValueUnit
Payment per period—USD
Total interest paid—USD
Total amount paid (including fees)—USD
Effective APR (annualized)2400.00%%
Estimated number of periods with extra payment—periods
Primary result—

Visualization

Methodology

Calculations use standard amortization math: periodic_rate = nominal APR / payments per year; payment is the annuity payment that amortizes principal over the term. Effective APR is annualized by compounding the periodic rate for the chosen frequency.

When fees are provided, they are added to total paid to show all-in cost. Term estimates with extra payments use iterative amortization logic; zero-interest loans use simple division by number of periods to avoid division-by-zero errors.

Numeric handling and disclosure follow general best practices for financial calculations and numeric reproducibility. For implementation and security guidance see NIST standards for numeric and software integrity. For disclosure and consumer protection, consult relevant regulatory guidance.

Worked examples

Example: $50,000 principal, 8.5% APR, 5 years, bi-weekly (26/y). Periodic rate = 0.085/26. Payment is computed with the annuity formula above and total interest is payment×n − principal.

Compare: same loan with monthly payments usually results in a different effective APR and different total interest; bi-weekly schedules can lower total interest by increasing payment frequency and shortening effective amortization period.

F.A.Q.

Will switching to bi-weekly payments always lower total interest?

Increasing payment frequency can reduce total interest because interest compounds less between payments and the principal is reduced earlier. The exact savings depend on whether the lender applies payments immediately and whether the lender charges additional fees. Use the comparison output to quantify differences.

Does this calculator produce an official APR disclosure?

No. This tool estimates APR effects and payments for planning and comparison. Official APR disclosures are provided by lenders and regulated by consumer protection rules. Always compare against the lender's Truth-in-Lending disclosure.

How accurate are the results?

Results are mathematically consistent with the formulas shown but assume exact application of periodic compounding and immediate application of payments. Rounding, payment posting rules, day-count conventions, and lender-specific practices can change outcomes. See the accuracy caveats and cited standards for implementation guidance.

How should I account for fees?

Enter upfront origination or similar fees in the fees field. Fees are included in total amount paid to help estimate all-in cost. APR and effective APR computations shown here use nominal APR entered by the user and do not re-calculate legal APR from fees; consult lender disclosures or a compliance professional for legal APR re-computation.

Sources & citations

Further resources

Versioning & Change Control

Audit record (versions, QA runs, reviewer sign-off, and evidence).

Record ID: 06b054d45292

What changed (latest)

v1.0.0 • 2025-11-10 • MINOR

Initial publication and governance baseline.

Why: Published with reviewed formulas, unit definitions, and UX controls.

Public QA status

PASS — golden 25 + edge 120

Last run: 2026-01-23 • Run: golden-edge-2026-01-23

Engine

v1.0.0

Data

Baseline (no external datasets)

Content

v1.0.0

UI

v1.0.0

Governance

Last updated: Nov 10, 2025

Reviewed by: Fidamen Standards Committee (Review board)

Credentials: Internal QA

Risk level: low

Reviewer profile (entity)

Fidamen Standards Committee

Review board

Internal QA

Entity ID: https://fidamen.com/reviewers/fidamen-standards-committee#person

Semantic versioning

  • MAJOR: Calculation outputs can change for the same inputs (formula, rounding policy, assumptions).
  • MINOR: New features or fields that do not change existing outputs for the same inputs.
  • PATCH: Bug fixes, copy edits, or accessibility changes that do not change intended outputs except for previously incorrect cases.

Review protocol

  • Verify formulas and unit definitions against primary standards or datasets.
  • Run golden-case regression suite and edge-case suite.
  • Record reviewer sign-off with credentials and scope.
  • Document assumptions, limitations, and jurisdiction applicability.

Assumptions & limitations

  • Uses exact unit definitions from the Fidamen conversion library.
  • Internal calculations use double precision; display rounding follows the unit's configured decimal places.
  • Not a substitute for calibrated instruments in regulated contexts.
  • Jurisdiction-specific rules may require official guidance.

Change log

v1.0.0 • 2025-11-10 • MINOR

Initial publication and governance baseline.

Why: Published with reviewed formulas, unit definitions, and UX controls.

Areas: engine, content, ui • Reviewer: Fidamen Standards Committee • Entry ID: 20eb1ae62bfc