Fidamen

Business Loan Refinance Calculator with Extra Payments

This calculator helps you compare an existing business loan to a proposed refinance and shows how adding extra payments (regular or one-time) affects payoff time and interest paid. Use conservative inputs for fees and realistic extra-payment schedules.

Results are estimates for planning and negotiation. They do not replace lender disclosures; verify exact numbers from loan agreements and amortization schedules.

Updated Nov 7, 2025QA PASS — golden 25 / edge 120Run golden-edge-2026-01-23

Governance

Record e3c950806d4c • Reviewed by Fidamen Standards Committee

Calculate payments, total interest, net savings after refinance costs, and an approximate break-even point measured in payment periods.

Inputs

Results

Updates as you type

Current loan periodic payment

$1,956.61

Refinance periodic payment

$1,887.12

Total interest remaining (current loan)

$17,396.89

Total interest (new loan)

$13,227.40

Estimated net interest savings after refinance costs

$2,169.49

Approximate break-even (periods)

28.7805

OutputValueUnit
Current loan periodic payment$1,956.61USD
Refinance periodic payment$1,887.12USD
Total interest remaining (current loan)$17,396.89USD
Total interest (new loan)$13,227.40USD
Estimated net interest savings after refinance costs$2,169.49USD
Approximate break-even (periods)28.7805periods
Primary result$1,956.61

Visualization

Methodology

Periodic payment is calculated using the standard amortizing loan formula: payment = r * PV / (1 - (1 + r)^-n), where r is the periodic interest rate and n is the number of periods.

For extra fixed periodic payments, payoff periods are estimated by solving the amortization equation for n using logarithms. One-time lump-sum payments are modeled as a principal reduction at the specified period and then the remaining amortization is recalculated.

Estimates exclude taxes, insurance, business operating covenants, or non-interest lender charges unless entered as refinance costs. When the periodic rate is zero, division-by-zero is avoided by linear amortization.

Worked examples

If your current loan has $100,000 remaining at 6.5% with 5 years left and a refinance offers 5.0% for 5 years with $2,000 fees, this tool calculates the change in periodic payment, total interest, and net savings after fees.

Adding a fixed extra payment of $100 per month to the current loan shows how many months you save and how much interest you avoid paying overall.

F.A.Q.

Are these results exact?

No. Results are mathematical estimates using standard amortization formulas. Actual lender schedules, timing of payments, rounding rules, day-count conventions, and any prepayment penalties can change outcomes. Use this calculator for planning and validate with lender statements.

Do you include refinance fees in savings?

Yes. Refinance costs entered are subtracted from interest savings to produce an estimated net savings figure.

How do extra payments affect my loan?

Regular extra payments reduce the principal faster, decreasing the number of periods needed to pay off the loan and reducing total interest. A one-time lump sum reduces principal immediately; the tool models its impact when you specify the payment period.

What if interest rate is zero?

For a 0% periodic rate the calculator treats amortization as linear: principal divided evenly over remaining periods to avoid divide-by-zero errors.

How should I interpret break-even periods?

Break-even is an approximate count of payment periods until cumulative payment savings equal refinance costs. If new periodic payment is higher than current payment, break-even is not meaningful.

Sources & citations

Further resources

External guidance

Versioning & Change Control

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

Record ID: e3c950806d4c

What changed (latest)

v1.0.0 • 2025-11-07 • 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 7, 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 • 2025-11-07 • 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: ff39cc3f5ba8