Balance Transfer Savings Calculator Formula

Understand the math behind the balance transfer savings calculator. Each variable explained with a worked example.

Use the Balance Transfer Savings Calculator

Formulas Used

Transfer Fee

transfer_fee_cost = fee_amount

Interest Saved During Intro

interest_saved = old_monthly_rate > 0 ? monthly_payment * intro_months - (balance - (monthly_payment * intro_months - balance * old_monthly_rate * intro_months)) : 0

Balance After Intro Period

remaining_after_intro = max(balance + fee_amount - monthly_payment * intro_months, 0)

Net Savings (vs Keeping Card)

net_savings = balance * old_monthly_rate * intro_months - fee_amount

Variables

VariableDescriptionDefault
balanceBalance to Transfer(USD)8000
current_aprCurrent APR(%)24
transfer_feeBalance Transfer Fee(%)3
intro_monthsIntro 0% APR Period(months)18
monthly_paymentMonthly Payment(USD)500
fee_amountDerived value= balance * transfer_fee / 100calculated
old_monthly_rateDerived value= current_apr / 12 / 100calculated

How It Works

Balance Transfer Strategy

A balance transfer moves high-rate credit card debt to a card with 0% introductory APR.

Cost-Benefit Analysis

Interest saved = Balance x Monthly Rate x Intro Months

Transfer fee = Balance x Fee Percentage (typically 3-5%)

Net savings = Interest Saved - Transfer Fee

Key Rules

  • Pay as much as possible during the 0% period
  • After the intro period, remaining balance accrues interest at the regular rate (often 18-25%)
  • Missing a payment may void the intro rate

    • Worked Example

    $8,000 at 24% APR, transfer to 0% card with 3% fee for 18 months, paying $500/month.

    balance = 8000current_apr = 24transfer_fee = 3intro_months = 18monthly_payment = 500
    1. 01Transfer fee = $8,000 x 3% = $240
    2. 02Interest saved = $8,000 x 2% x 18 = $2,880 (approximate)
    3. 03Net savings = $2,880 - $240 = $2,640
    4. 04Balance after 18 months = $8,240 - ($500 x 18) = $0 (paid off in ~17 months)

    Ready to run the numbers?

    Open Balance Transfer Savings Calculator