Balance Transfer Calculator
This calculator estimates the timeline and total cost when moving a credit card balance into a promotional APR and then repaying at your regular APR after the promo. It includes the common balance transfer fee and optional other fees so you can compare the transfer scenario to keeping your current balance.
Results are estimates based on standard amortization math and numeric rounding conventions. Use the monthly payment you realistically expect to make; a lower payment increases time and interest. For compliance and reproducibility, the tool follows established numeric practices and documents assumptions below.
Governance
Record aa9aa797b58c • Reviewed by Fidamen Standards Committee
Calculate payment and cost when transferring a single balance into a promotional APR for a fixed number of months, then repaying at your regular APR.
Inputs
Results
Transfer fee
$150.00
Remaining balance after promo
$3,350.00
Months after promo
—
Total months to payoff
—
Total paid (includes fees)
—
Estimated total interest
—
| Output | Value | Unit |
|---|---|---|
| Transfer fee | $150.00 | USD |
| Remaining balance after promo | $3,350.00 | USD |
| Months after promo | — | months |
| Total months to payoff | — | months |
| Total paid (includes fees) | — | USD |
| Estimated total interest | — | USD |
Visualization
Methodology
We model the transfer as: new principal = original balance + transfer fee + other one-time fees. During the promotional period we apply the promotional monthly rate to any outstanding balance and subtract monthly payments. After the promo ends, remaining balance is amortized at the regular monthly rate using the standard loan amortization relationship.
To avoid misleading outputs the calculator: uses monthly compounding consistent with typical credit card practice, handles zero-interest promo or zero regular APR as a special case (simple division), and rounds months up to the next whole month when partial months remain.
Worked examples
Example: $5,000 balance, 3% transfer fee, 0% promo for 12 months, $150 monthly payment. The transfer fee adds $150 to the principal; payments during the promo reduce principal and any remaining balance is amortized at your regular APR.
Example: If your promotional APR is 0% and your monthly payment equals the minimum, you may still owe a remaining balance after the promo which will then accrue interest at the regular APR.
F.A.Q.
Does the calculator guarantee exact results my bank will show?
No. This calculator provides estimates. Individual statements can differ due to daily interest conventions, minimum payment rules, rounding differences, billing cycles, grace periods, backdated fees, late fees, or promotional terms not captured here. Use values from your card agreement for best accuracy.
How does the tool handle a 0% promotional APR?
If the promotional APR is 0%, the calculator treats interest during the promo as zero and simply subtracts your monthly payments from principal. Any remaining balance at the end of the promo is amortized at the regular APR.
What if my monthly payment is less than the interest charged?
If the monthly payment is insufficient to cover interest after the promo, the model's amortization formula will produce very large or undefined payoff months. The calculator will show a high month count; increase the monthly payment to a level that covers accrued interest plus some principal to ensure payoff.
Are fees included in the totals?
Yes. Transfer fee and any other one-time fees entered are added to principal and included in total paid and total interest calculations.
Sources & citations
- Numeric rounding and floating-point considerations (IEEE 754) — https://standards.ieee.org/standard/754-2019.html
- Information security and data integrity guidance (NIST) — https://www.nist.gov
- Information security management standard (ISO/IEC 27001) — https://www.iso.org/isoiec-27001-information-security.html
- Workplace and operational safety guidance (OSHA) — https://www.osha.gov
- CFPB — Consumer Financial Protection Bureau — https://www.consumerfinance.gov/
- Federal Reserve — Consumer Credit — https://www.federalreserve.gov/releases/g19/current/
- IRS Publication 17 — Your Federal Income Tax — https://www.irs.gov/publications/p17
Further resources
Related tools
Versioning & Change Control
Audit record (versions, QA runs, reviewer sign-off, and evidence).
Record ID: aa9aa797b58cWhat changed (latest)
v1.0.0 • 2025-11-05 • 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 • 2025-11-05 • 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 5, 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 • 2025-11-05 • 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: c995ac716f34