Fidamen

Business Loan Extra Payments Calculator

This calculator models business loan amortization for bi‑weekly (26 payments per year) schedules and provides tools to see how recurring extra principal payments change payoff time and total interest. It also contains a comparison mode between standard monthly and bi‑weekly payment cadences.

Results are estimates based on standard amortization mathematics. Use the tool to test different extra payment amounts, terms, and rates to plan cash flow and verify lender statements.

Updated Nov 9, 2025QA PASS — golden 25 / edge 120Run golden-edge-2026-01-23

Governance

Record ba83756a5b51 • Reviewed by Fidamen Standards Committee

Calculates base bi‑weekly payment, effect of recurring principal extra payments, estimated new payoff count, total interest and time saved. Recurring extra payments assumed to begin immediately unless user offsets start period.

Inputs

Results

Updates as you type

Bi‑weekly payment (no extra)

$891.26

Bi‑weekly payment (with recurring extra)

$891.26

Estimated payments until payoff (with extras)

—

Total interest (no extra)

$15,863.36

Total interest (with extra)

—

Estimated interest saved

—

Estimated time saved (years)

—

OutputValueUnit
Bi‑weekly payment (no extra)$891.26USD
Bi‑weekly payment (with recurring extra)$891.26USD
Estimated payments until payoff (with extras)——
Total interest (no extra)$15,863.36USD
Total interest (with extra)—USD
Estimated interest saved—USD
Estimated time saved (years)—years
Primary result$891.26

Visualization

Methodology

Calculations use conventional amortization formulas and an algebraic rearrangement to estimate the number of payments when recurring extras are applied. Numeric operations follow IEEE 754 floating‑point norms for stability. Data handling and recommended practices reference NIST and ISO guidance for accuracy, reproducibility, and safe storage.

Outputs are rounded and presented as estimates. For final payoff figures, confirm with your lender because actual schedules can include fees, daily interest accrual, or different compounding conventions not captured here.

Worked examples

Example: $100,000 loan, 6% APR, 5 years. Bi‑weekly scheduled payment (no extras) computed with payments_per_year=26. Add a recurring $50 extra per bi‑weekly payment to see new payoff estimate and interest saved.

Compare mode: same loan compared on monthly (12/yr) vs bi‑weekly (26/yr) schedules to show structural interest differences when no extras are applied.

F.A.Q.

Are these results exact for my loan?

These are estimates based on standard amortization and assume interest compounds at the periodic rate used here. Actual lender schedules may differ due to daily interest, fees, prepayment rules, or timing. Use lender payoff quotes for legally binding numbers.

Does bi‑weekly always save interest?

Bi‑weekly can reduce interest if it results in extra principal applied sooner (for example 26 payments instead of 12). The savings depend on whether the lender treats bi‑weekly payments as extra principal or simply a payment schedule. Confirm with your lender how payments are applied.

How accurate are the time and interest savings estimates?

Estimates follow proven algebraic formulas and IEEE numeric conventions, but are sensitive to rounding and payment timing. For critical decisions, cross‑check results with an amortization schedule from your lender or a certified accountant.

What if I make a one‑time extra payment instead of recurring extras?

This tool models recurring extras. A one‑time extra reduces the principal immediately and will shorten the remaining schedule; for a precise one‑time scenario, use a tailored amortization schedule or consult an amortization table.

Sources & citations

Further resources

External guidance

Versioning & Change Control

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

Record ID: ba83756a5b51

What changed (latest)

v1.0.0 • 2025-11-09 • 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 9, 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 • 2025-11-09 • 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: 5bbcdafb6698