Fidamen

Student Loan Refinance Calculator with Bi-Weekly Payments

This calculator compares a standard refinanced monthly amortization to two bi‑weekly options: (1) a true bi‑weekly amortization that uses 26 equal periods per year and (2) an accelerated approach where you pay half of the monthly payment every two weeks (resulting in 26 payments a year). Use the inputs to estimate payments, total interest, and how much time and interest you may save by switching payment frequency.

Results are estimates intended for planning. Actual payoff timing and interest depend on loan terms, lender compounding rules, payment posting dates, and any prepayment rules or fees.

Updated Nov 28, 2025QA PASS — golden 25 / edge 120Run golden-edge-2026-01-23

Governance

Record 587a16126c5a • Reviewed by Fidamen Standards Committee

Recalculates the three scenarios and presents direct comparisons: interest saved and time saved when choosing bi‑weekly options vs monthly.

Inputs

Results

Updates as you type

Monthly payment (comparison)

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Bi‑weekly payment (26/year, comparison)

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Accelerated bi‑weekly payment (half of monthly)

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Interest saved (true bi‑weekly vs monthly)

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Interest saved (accelerated vs monthly)

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Time saved (years) — true bi‑weekly vs monthly

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Time saved (years) — accelerated vs monthly

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OutputValueUnit
Monthly payment (comparison)—USD
Bi‑weekly payment (26/year, comparison)—USD
Accelerated bi‑weekly payment (half of monthly)—USD
Interest saved (true bi‑weekly vs monthly)—USD
Interest saved (accelerated vs monthly)—USD
Time saved (years) — true bi‑weekly vs monthly0years
Time saved (years) — accelerated vs monthly—years
Primary result—

Visualization

Methodology

Monthly amortization uses a standard annuity formula with monthly compounding: the periodic interest rate is APR / 12, and the number of periods is term years × 12.

True bi‑weekly amortization treats each bi‑weekly period as an interest period (26 periods per year) and applies the annuity formula at that period rate and schedule.

Accelerated bi‑weekly is modeled by taking half of the baseline monthly payment and applying it every two weeks (26 payments/year). The calculator estimates payoff by solving the annuity expression for the required number of periods given that periodic payment.

Refinance fees entered are allocated evenly across periods for display purposes to show an approximate effect on periodic payment and total interest. This simplifies presentation; if fees are rolled into balance or financed differently, adjust the principal or fee accordingly.

F.A.Q.

Which bi‑weekly method saves more interest?

Typically the accelerated bi‑weekly approach (paying half of monthly every two weeks) reduces interest more than a monthly schedule because you make the equivalent of an extra monthly payment per year. A true bi‑weekly amortization can produce similar or different savings depending on the lender's compounding frequency and whether the loan supports bi‑weekly schedules.

Are these results exact for my lender?

No. This tool provides estimates. Exact amounts depend on lender-specific compounding periods, payment allocation rules, payment posting times, returned payments, and any mandatory fees. Always verify with your lender for an exact amortization schedule.

What if the interest rate is zero?

When the interest rate equals zero, periodic payment formulas reduce to simple principal division by number of periods. The calculator handles that case by using principal divided by number of periods.

How accurate is this calculator and what standards guide it?

This calculator uses standard annuity formulas for amortization. For reliability and traceability we follow accepted engineering and measurement practices and cite relevant standards for computational accuracy. See the citations for reference. All results are estimates and subject to rounding and modeling assumptions.

Sources & citations

Further resources

Versioning & Change Control

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

Record ID: 587a16126c5a

What changed (latest)

v1.0.0 • 2025-11-28 • 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 28, 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 • 2025-11-28 • 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: 531f62469b28