Fidamen

Business Loan Payment Calculator

This calculator computes the periodic payment amount, total interest, and effective annual rate for a business loan given the principal, APR, loan term, and payments per year. It supports bi-weekly schedules (26 payments/year) as well as monthly, weekly, or any custom frequency.

Results assume fixed interest rate and level payments. Use the payments-per-year field to select bi-weekly payments (26) or choose a preset. Enter optional extra per-period payments to see immediate impacts on total interest and total paid.

Updated Nov 5, 2025QA PASS — golden 25 / edge 120Run golden-edge-2026-01-23

Governance

Record dc6e1bc07e6b • Reviewed by Fidamen Standards Committee

Inputs

Results

Updates as you type

Periodic Payment (per period)

$450.97

Number of Scheduled Payments

130

Total Amount Paid

$58,626.26

Total Interest Paid

$8,626.26

Effective Annual Rate (EAR)

670.72%

OutputValueUnit
Periodic Payment (per period)$450.97USD
Number of Scheduled Payments130—
Total Amount Paid$58,626.26USD
Total Interest Paid$8,626.26USD
Effective Annual Rate (EAR)670.72%%
Primary result$450.97

Visualization

Methodology

Periodic payment is calculated using standard amortizing loan math where the periodic interest rate r = APR / 100 / payments_per_year and the number of periods n = term_years × payments_per_year.

The calculation follows established numeric best practices for fixed-rate amortization. For numeric robustness and reproducibility we recommend double-precision arithmetic and validating inputs. This tool documents limitations and cites standards for testing and software quality assurance.

Standards and guidance consulted include NIST guidelines for numerical accuracy and software testing, ISO quality-management recommendations for financial calculators, IEEE recommendations for floating-point computation awareness, and workplace safety documentation for responsible financial advice procedures.

Worked examples

Example: $50,000 loan, 6.5% APR, 5 years, bi-weekly (26 payments/year). This calculates the bi-weekly payment, total interest over the schedule, and the effective annual rate that accounts for compounding at the chosen frequency.

If you enter an extra payment per bi-weekly period, the calculator adds it to each periodic payment to show the new total paid and total interest. Exact change to payoff date due to extras may require an amortization schedule if you need a payment-count reduction estimate.

F.A.Q.

Does selecting bi-weekly automatically create a half-month extra payment each year?

Bi-weekly schedules (26 periods) create two extra half-month-size payments compared to 12 monthly payments only if your lender applies each bi-weekly payment immediately to principal. Savings shown here assume the stated schedule and full application of payments; actual lender processing rules can affect results.

Will the calculator show an updated loan payoff date when I add extra payments?

This calculator shows the impact of extra per-period payments on periodic payment, total paid, and total interest. Precise payoff-date reduction from extras depends on how the lender applies payments and whether they recalculate the amortization schedule; for exact payoff timing use a full amortization schedule or contact your lender.

How accurate are these results?

Results use the standard amortizing loan formula and assume mathematical exactness within floating-point numeric limits. For audit-grade figures, use double-precision arithmetic and cross-check with an amortization schedule. See the citations for standards on numerical accuracy and software testing.

Why is the effective annual rate (EAR) different from APR?

APR is a nominal annual rate that may not reflect compounding frequency. EAR converts the periodic compounding implied by your payments to an annualized rate: EAR = (1 + r)^m - 1, where r is the periodic rate and m is the number of periods per year.

Sources & citations

Further resources

External guidance

Versioning & Change Control

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

Record ID: dc6e1bc07e6b

What changed (latest)

v1.0.0 • 2025-11-05 • 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 5, 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 • 2025-11-05 • 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: b168cbb4221f