Auto Loan Payment Fixed Rate Estimator
Fixed-rate auto loan estimator designed for budgeting accuracy and Regulation Z alignment.
Includes negative equity, taxes, dealer fees, and operating costs to model total cost of ownership.
Governance
Record 1cd6b3263a79 • Reviewed by Fidamen Standards Committee
Inputs
Results
Net trade-in equity
$0.00
Taxable vehicle base
$27,000.00
Estimated sales tax
$2,160.00
Financed amount
$29,160.00
APR used in calculation
0
Periodic payment
$486.00
Total of all payments
—
Total interest paid
—
Estimated operating costs
$0.00
Total cost of ownership
—
| Output | Value | Unit |
|---|---|---|
| Net trade-in equity | $0.00 | USD |
| Taxable vehicle base | $27,000.00 | USD |
| Estimated sales tax | $2,160.00 | USD |
| Financed amount | $29,160.00 | USD |
| APR used in calculation | 0 | % |
| Periodic payment | $486.00 | USD |
| Total of all payments | — | USD |
| Total interest paid | — | USD |
| Estimated operating costs | $0.00 | USD |
| Total cost of ownership | — | USD |
Visualization
Secure calculation & market rates
Disclosures, privacy posture, and live rate governance for this calculator.
Data privacy
Inputs are processed in-session only. No user data storage is required.
2026 auto loan rate tiers
Base APR is sourced from the live 2026 feed and adjusted by credit tier multipliers.
| Credit tier | Multiplier |
|---|---|
| Excellent | 0.85x |
| Good | 1x |
| Fair | 1.25x |
| Poor | 1.6x |
2026 live auto loan APR feed — https://api.fidamen.com/rates/auto-loan-apr?year=2026
2026 sales tax baseline feed — https://api.fidamen.com/tax/sales?year=2026
How This Calculator Works
Limitations
Methodology
Amortization uses a level-payment fixed-rate formula with deterministic rounding at the display layer.
APR estimates are sourced from a live 2026 market feed and adjusted by credit tier multipliers.
Key takeaways
2026_market_rate_table
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F.A.Q.
How is negative equity handled?
Negative equity equals amount owed on trade-in minus trade-in value and increases the financed amount.
Why do APR and interest rate differ?
APR reflects the cost of credit and can include certain finance charges, while the interest rate reflects the base cost of borrowing.
Does this replace lender disclosures?
No. Final lender disclosures control and may differ due to lender-specific fees or timing.
Sources & citations
- CFPB Regulation Z - 12 CFR 1026.22 — https://www.consumerfinance.gov/rules-policy/regulations/1026/22/
- CFPB Appendix J - APR computations for closed-end credit — https://www.consumerfinance.gov/rules-policy/regulations/1026/j/
Further resources
Versioning & Change Control
Audit record (versions, QA runs, reviewer sign-off, and evidence).
Record ID: 1cd6b3263a79What changed (latest)
v2.1.0 • 2026-01-28 • 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
Versioning & Change Control
Audit record (versions, QA runs, reviewer sign-off, and evidence).
What changed (latest)
v2.1.0 • 2026-01-28 • 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
v2.1.0
Data
Baseline (no external datasets)
Content
v2.1.0
UI
v1.0.0
Governance
Last updated: Jan 28, 2026
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
v2.1.0 • 2026-01-28 • 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: d54c2c281ef4