Balance Transfer Calculator

Written by Great Medico

Updated September 25, 2026 •3 min read

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Balance Transfer Calculator turns the values on the form into a focused planning estimate. It compares estimated interest on the current card during the promotional period with the transfer fee and promotional-rate interest on a balance transfer and keeps the arithmetic visible enough to sanity-check.

What this calculator does

Balance Transfer Calculator compares estimated interest on the current card during the promotional period with the transfer fee and promotional-rate interest on a balance transfer. The form asks for current card balance, current card apr, promotional transfer apr, promotional period, balance transfer fee, and monthly payment. The result should therefore be read as a calculation from those displayed assumptions, not as live market, lender, tax, or government-program data unless the page explicitly supplies such a feed.

How to use it

Enter Current card balance, Current card APR, Promotional transfer APR, Promotional period, Balance transfer fee, and Monthly payment. Keep monetary inputs in one currency; the currency selector formats results and does not convert exchange rates. Enter rates and percentages on the scale shown by the field label; do not silently switch between a decimal and a percent. Keep time values in the period shown on the form so a monthly figure is not accidentally entered as an annual one or vice versa. Before calculating, recheck Current card balance, Current card APR, Promotional transfer APR against the source values you intend to model. If a default value is already filled in, confirm that it matches the scenario you actually want to test rather than assuming the preset is current or personally appropriate.

How the calculation works

Transfer fee = current balance × transfer-fee rate. Old-card interest is approximated from balance × current APR × promo months/12. New-card interest uses balance plus fee × promotional APR × promo months/12. Estimated savings = old interest − new interest − transfer fee. This is the calculation method to use when checking the result from Balance Transfer Calculator; values not represented by a visible input should not be inferred as part of the model.

Example

On a $5,000 balance, a 3% transfer fee is $150. Over an 18-month promo period, the calculator compares simplified interest at the current 22% APR with interest at the entered transfer APR, then subtracts the $150 fee from the modeled savings.

How to interpret the result

A positive savings estimate means the promotional transfer is cheaper under these simplified assumptions. A negative value means the transfer fee and promotional interest outweigh the modeled old-card interest. Keep the assumptions with the result so a later recalculation can be compared consistently.

Limitations and notes

Real credit-card interest is based on daily balances and payments, and promotional rates can expire or apply only to transferred amounts. New purchases, payment allocation, minimum payments, late fees, and post-promo APR are not fully modeled. Rounding and timing conventions can cause a real statement or account balance to differ slightly from the model.