Fidamen

Boat Loan Balloon Payment Calculator

This calculator estimates periodic payments and the final balloon payment for a boat loan. It supports either monthly or bi‑weekly schedules and two payment methods: amortizing payments that leave a balloon at maturity, or interest‑only payments followed by a balloon.

Use the fields to enter loan amount, annual interest rate, loan term, payment frequency (monthly or bi‑weekly), and the balloon as either a fixed amount or a percent of the original loan. Results are rounded for display; see accuracy notes.

Updated Nov 12, 2025QA PASS — golden 25 / edge 120Run golden-edge-2026-01-23

Governance

Record ed3736475f25 • Reviewed by Fidamen Standards Committee

Compute the periodic payment needed to amortize the loan amount minus the balloon over the scheduled payments, with a remaining balloon paid at maturity.

Inputs

Advanced inputs

Balloon amount (absolute)

Balloon amount (percent)

Results

Updates as you type

Periodic payment

$450.97

Balloon payment (maturity)

$0.00

Total paid (payments + balloon)

$58,626.26

Total interest paid

$8,626.26

OutputValueUnit
Periodic payment$450.97USD
Balloon payment (maturity)$0.00USD
Total paid (payments + balloon)$58,626.26USD
Total interest paid$8,626.26USD
Primary result$450.97

Visualization

Methodology

For the amortizing-with-balloon method, the tool computes the periodic interest rate by dividing the annual nominal rate by the payments per year. It calculates the payment that amortizes the principal portion (loan minus balloon) across the scheduled payments using the standard annuity formula. The balloon remains as a final lump sum at maturity.

For the interest-only method, periodic payments equal interest on the full principal; the principal (or specified balloon) is paid at maturity. All computations assume constant nominal interest rate and fixed payment schedule.

Worked examples

Example 1: $50,000 loan, 6.5% annual, 5 years, bi‑weekly payments (26/year), 20% balloon: calculator shows the bi‑weekly payment to amortize $40,000 over 130 payments and a $10,000 balloon at maturity.

Example 2: $30,000 loan, 5.0% annual, 3 years, monthly payments, interest-only method, balloon equals full principal: monthly payments cover interest only and the $30,000 principal is due at maturity.

F.A.Q.

Does bi‑weekly frequency reduce the total interest compared with monthly?

Bi‑weekly frequency changes the number of compounding periods and payment timing. If payments are sized and scheduled to match nominal rate conventions, bi‑weekly can lead to a different amortization path; use the calculator to compare. This tool assumes nominal annual interest divided by payments-per-year.

What rounding and accuracy can I expect?

Displayed values are rounded to typical currency precision. Internal calculations use standard floating arithmetic; results may differ slightly from lender statements due to day-count conventions, compounding rules, fees, or rounding. See citations for standards and the accuracy caveat below.

Is this a loan offer or a statement of legal terms?

No. This calculator provides estimates only and is not an offer, disclosure, or legal advice. Consult your lender for exact payoff schedules, fees, and contract terms.

Can I model a balloon larger than the loan or zero?

The tool allows explicit balloon amounts or percentages. A balloon greater than the loan is mathematically allowed but unlikely in practice; check inputs. If 'No balloon' is selected, the loan amortizes fully over the term.

Sources & citations

Further resources

External guidance

Versioning & Change Control

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

Record ID: ed3736475f25

What changed (latest)

v1.0.0 • 2025-11-12 • 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 12, 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 • 2025-11-12 • 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: a7143e679114