Mortgage Balloon Payment Calculator with Bi-Weekly Payments
This tool estimates the scheduled periodic payment for a loan that amortizes over a specified amortization period and computes the outstanding balance (the balloon payment) at an earlier balloon date. It supports bi-weekly schedules (commonly 26 payments/year) and any other payment frequency you enter.
Use the fields to enter loan principal, APR, full amortization term, months until the balloon payment, and payments per year. Results are estimates; they do not include fees, escrow, taxes, insurance, prepayment penalties, or lender rounding conventions.
Governance
Record 373828b1e371 • Reviewed by Fidamen Standards Committee
Computes periodic payment based on amortization schedule, then computes outstanding balance at the balloon date (expressed in months). Designed for bi-weekly schedules when payment_frequency is 26.
Inputs
Results
Scheduled periodic payment
$808.98
Balloon payment (remaining balance)
$265,764.35
Remaining balance at balloon date
$265,764.35
Interest paid through balloon date
$70,931.41
Payments until balloon
130
| Output | Value | Unit |
|---|---|---|
| Scheduled periodic payment | $808.98 | USD |
| Balloon payment (remaining balance) | $265,764.35 | USD |
| Remaining balance at balloon date | $265,764.35 | USD |
| Interest paid through balloon date | $70,931.41 | USD |
| Payments until balloon | 130 | payments |
Visualization
Methodology
Periodic payment is computed using standard amortizing loan formulas converting annual APR to the periodic rate by dividing by payments per year and solving the annuity payment formula for the scheduled payment.
Remaining balance at the balloon date is calculated by applying the amortization balance formula after the number of payments that occur before the balloon date. Formulas assume consistent periodic payments and interest charged per period at the periodic rate.
Numeric computations follow IEEE floating-point conventions (see IEEE 754) and results are rounded to cents by default. Development and quality processes reference ISO 9001 principles for quality management and NIST guidance for measurement and testing. OSHA is cited as a reminder that organizational compliance and operational safety practices are outside the scope of this calculator but important for operations teams.
Worked examples
Example 1: $300,000 principal, 5% APR, 25-year amortization, balloon at 60 months, bi-weekly (26/year). The tool returns the periodic bi-weekly payment, remaining balance at 5 years, and total interest paid through that date.
Example 2: For monthly schedule set payments per year to 12 and the balloon months to your contract's balloon timing to compute the monthly scheduled payment and balloon amount.
F.A.Q.
How accurate are the results?
Results are mathematically accurate to the formulas used and subject to floating-point rounding. They are estimates and do not include lender-specific rounding rules, fees, taxes, escrow, or prepayment penalties. For legally binding payoff figures contact the lender. The calculator follows IEEE 754 conventions for numeric operations and rounds monetary outputs to the specified number of decimal places (default two).
Can I use this for bi-weekly payments?
Yes. Set payments per year to 26 for bi-weekly schedules. Note that 'bi-weekly' (26 payments/year) differs from 'semi-monthly' (24 payments/year); results will differ.
What if the interest rate is zero?
The standard amortization formula divides by the periodic rate and is not directly defined for zero interest. In a true zero-interest loan, periodic payment equals principal divided by total scheduled payments. If you enter a zero APR, verify the scheduled payment and remaining balance logically; consult lender documentation for special cases.
Does this include taxes, insurance, or escrow?
No. This calculator only computes principal and interest schedules. It does not include taxes, insurance, escrow, HOA, lender fees, or closing costs.
Are there regulatory or standards references?
The numeric implementation references IEEE 754 floating-point arithmetic for predictable numeric behavior. Quality and testing reference ISO 9001 principles and NIST resources for validation and traceability. OSHA is cited for organizational compliance context; it does not apply to financial calculations directly.
Sources & citations
- IEEE Standard for Floating-Point Arithmetic (IEEE 754) — https://standards.ieee.org/standard/754-2019.html
- ISO 9001 Quality Management — https://www.iso.org/iso-9001-quality-management.html
- National Institute of Standards and Technology (NIST) — https://www.nist.gov
- Occupational Safety and Health Administration (OSHA) — https://www.osha.gov
- CFPB — Understand Loan Options — https://www.consumerfinance.gov/owning-a-home/loan-options/
- CFPB — Explore Interest Rates — https://www.consumerfinance.gov/owning-a-home/explore-rates/
- Fannie Mae — Loan Terms Glossary — https://www.fanniemae.com/glossary
Further resources
Versioning & Change Control
Audit record (versions, QA runs, reviewer sign-off, and evidence).
Record ID: 373828b1e371What changed (latest)
v1.0.0 • 2025-11-30 • 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
Versioning & Change Control
Audit record (versions, QA runs, reviewer sign-off, and evidence).
What changed (latest)
v1.0.0 • 2025-11-30 • 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 30, 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 • 2025-11-30 • 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: bc918395d632