Fidamen

Business Loan Interest Calculator with Bi-Weekly Payments

This calculator estimates periodic payments and lifetime cost for an amortizing business loan when payments are made on a bi‑weekly schedule (26 payments per year) or any custom payment frequency. Enter the principal, the nominal annual interest rate (APR), loan term in years, and the number of payments per year. Optionally add a fixed extra amount applied to each payment to see its effect on total paid.

Results are estimates intended for planning and comparison. They assume a nominal APR applied to each payment period and a fixed payment schedule; actual bank statements, fees, compounding conventions, or regulatory rounding may produce small differences. Always verify with your lender for the official amortization schedule.

Updated Nov 19, 2025QA PASS — golden 25 / edge 120Run golden-edge-2026-01-23

Governance

Record 0cf6113e1b42 • Reviewed by Fidamen Standards Committee

Inputs

Results

Updates as you type

Scheduled payment per period

$445.63

Payment per period (with extra)

$445.63

Total number of payments

130

Total paid (estimate)

$57,931.68

Total interest paid (estimate)

$7,931.68

Equivalent monthly payment (estimate)

$965.53

OutputValueUnit
Scheduled payment per period$445.63USD
Payment per period (with extra)$445.63USD
Total number of payments130periods
Total paid (estimate)$57,931.68USD
Total interest paid (estimate)$7,931.68USD
Equivalent monthly payment (estimate)$965.53USD
Primary result$445.63

Visualization

Methodology

We convert the nominal annual interest rate to a periodic rate by dividing APR by 100 and by the number of payments per year. The standard amortizing payment formula is used to calculate the scheduled payment per period.

If a constant extra payment is entered, it is added to each periodical payment for the purpose of computing total paid over the original term. This calculator does not perform a period‑by‑period amortization with early payoff date adjustment; it provides an estimate of total payments and interest under the constant extra payment assumption for the stated term.

F.A.Q.

Can I use this for true bi‑weekly acceleration (split monthly payments into bi‑weekly to get extra payments)?

This tool assumes N payments per year (default 26). It provides estimates for regular bi‑weekly schedules but does not automatically model specific lender rules that take half‑monthly vs bi‑weekly differences or apply extra payments to principal on different days. For exact accelerated payoff dates, use a period‑by‑period amortization schedule from your lender or an amortization tool that simulates each payment date.

What should I enter for APR vs nominal rate?

Enter the nominal annual interest rate your lender quotes (APR as a percent without the % sign). If your lender provides an effective annual rate or includes fees in APR, verify how those are applied; results will differ if fees alter the effective financing cost.

Is the total paid calculation exact if I enter an extra payment?

Total paid shown is an estimate based on adding the constant extra payment to each scheduled periodic payment across the stated term. It does not recalculate the reduced payoff date or stop payments once principal reaches zero. For precise early payoff schedules, use a full amortization simulation.

How accurate are these results?

Results use standard amortization formulas and common math functions. They are accurate for estimate and planning purposes but may differ from lender statements due to rounding rules, payment timing conventions, compounding differences, fees, or regulatory rounding. See citations for standards on numeric accuracy and testing.

Sources & citations

Further resources

External guidance

Versioning & Change Control

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

Record ID: 0cf6113e1b42

What changed (latest)

v1.0.0 • 2025-11-19 • 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 19, 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 • 2025-11-19 • 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: 960fd131c4bf