Fidamen

RV Loan Interest Calculator with Extra Payments

This calculator estimates scheduled payments, the effect of recurring extra payments, the estimated payoff time, and approximate interest saved when repaying an RV loan. Enter the loan principal, annual interest rate, term, payment frequency, and any recurring extra payment per period.

Results are estimates for planning and comparison. They assume fixed interest rate, fixed payment schedule, and that extra payments are applied directly toward principal at each payment.

Updated Nov 4, 2025QA PASS — golden 25 / edge 120Run golden-edge-2026-01-23

Governance

Record fa253b5e2208 • Reviewed by Fidamen Standards Committee

Inputs

Results

Updates as you type

Scheduled payment per period

$435.55

Payment per period with recurring extra

—

Scheduled number of payments (no extra)

180

Estimated number of payments with recurring extra

180

Estimated years to payoff with recurring extra

—

Total interest paid (no extra)

—

Estimated total interest paid (with recurring extra)

—

Estimated interest saved (approx.)

—

OutputValueUnit
Scheduled payment per period$435.55—
Payment per period with recurring extra——
Scheduled number of payments (no extra)180—
Estimated number of payments with recurring extra180—
Estimated years to payoff with recurring extra—years
Total interest paid (no extra)——
Estimated total interest paid (with recurring extra)——
Estimated interest saved (approx.)——
Primary result$435.55

Visualization

Methodology

The tool uses standard amortization mathematics to compute the scheduled periodic payment and total interest for the nominal term.

If a recurring extra payment is supplied, the calculator treats the combined amount (scheduled payment plus recurring extra) as the periodic payment and solves for the number of periods required to amortize the loan using logarithmic inversion of the annuity formula.

Calculations are performed with typical floating-point arithmetic; minor rounding differences may occur compared with lender statements.

F.A.Q.

How accurate are these results?

Outputs are mathematical estimates based on the inputs and the formulas shown. They depend on numerical precision of the environment; small rounding differences may exist compared to lender amortization tables. Consult your loan contract for exact amounts.

Does this calculator include fees, taxes, or insurance?

No. This tool only models principal and interest with fixed rate amortization. It does not include origination fees, late fees, taxes, insurance, gap products, or other charges that may be included by a lender.

What if interest rate changes or payments are not perfectly regular?

This model assumes a fixed interest rate and regular payments. Variable rates, skipped payments, one-time lumpsum prepayments, or changes in payment amount require a different calculation or a detailed amortization schedule.

Are the calculations compliant with any standards?

The numerical approach follows standard financial mathematics for annuities and amortization. Numerical rounding and floating-point behavior follow general computing standards; see IEEE 754 for floating-point arithmetic considerations. For quality management and traceability of calculations, ISO 9001 practices are recommended. Measurement and computational accuracy guidance can be found at NIST.

Is this financial or legal advice?

No. This tool provides estimates for planning only and is not financial, tax, or legal advice. Consult a licensed financial professional or your loan servicer for binding figures and personalized guidance.

Sources & citations

Further resources

Versioning & Change Control

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

Record ID: fa253b5e2208

What changed (latest)

v1.0.0 • 2025-11-04 • 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 4, 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 • 2025-11-04 • 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: d62da50aaddb