How to Calculate Which Debt to Pay Off First on $55,700: The 4-Step Formula That Saves Up to $6,200
How to Calculate Which Debt to Pay Off First on $55,700: The 4-Step Formula That Saves Up to $6,200
Here's a scenario that lands in a lot of inboxes this time of year.
You've got a $3,100 tax refund sitting in your checking account. NerdWallet's April reader questions are full of people in exactly this spot, asking the same thing: should I pay down debt or save it? But that's actually the wrong question. The real question is: which debt, in what order, using which payoff mechanism — and how do I calculate that?
The math isn't complicated once you break it into steps. But most people skip the calculation entirely and rely on gut instinct or a rule of thumb they half-remember. That gap between the rule-of-thumb answer and the calculated answer is where thousands of dollars disappear.
Let's walk through a real scenario, step by step.
The Scenario: $55,700 Across 6 Accounts
Meet the numbers. Six debts, $1,800/month available (after minimums and basic living), and a $3,100 tax refund to deploy.
| Debt | Balance | APR | Monthly Minimum |
|---|---|---|---|
| CC1 (rewards card) | $8,400 | 24.99% | $168 |
| CC2 (store card) | $6,300 | 21.49% | $126 |
| Personal loan | $12,800 | 11.99% | $284 |
| Auto loan | $14,300 | 7.24% | $317 |
| Student loan | $9,900 | 6.54% | $110 |
| Medical debt | $4,000 | 0% | $80 |
| Total | $55,700 | $1,085 |
Total minimum payments: $1,085/month. That leaves $715/month to deploy strategically — plus the $3,100 refund as a one-time lump sum.
The question isn't "should I pay debt?" It's "in what sequence, and through which vehicle?"
Step 1: Calculate the Effective APR for Each Debt
Nominal APR is not effective APR. Two adjustments matter here.
Tax deductibility. Student loan interest is deductible up to $2,500/year if your MAGI is under $85,000 (single) or $175,000 (married). At a 22% federal tax bracket, the effective rate on that 6.54% student loan becomes:
6.54% × (1 - 0.22) = 5.10% effective APR
HELOC interest is also potentially deductible, but only if used to buy, build, or substantially improve the home — the IRS post-2017 rules specifically exclude HELOC proceeds used to consolidate consumer debt from deductibility. Don't assume that deduction applies.
Credit card rates are higher than they look. Average credit card APR as of April 2026 sits around 24.4% per the Federal Reserve's most recent consumer credit data. Both cards in this scenario are right in that range — meaning there's no good news to find in the fine print.
Revised effective APR ranking:
| Debt | Effective APR |
|---|---|
| CC1 | 24.99% |
| CC2 | 21.49% |
| Personal loan | 11.99% |
| Auto loan | 7.24% |
| Student loan | 5.10% (after deduction) |
| Medical debt | 0% |
This is your payoff priority list for the pure avalanche strategy. But the avalanche isn't always the optimal vehicle.
Step 2: Model Three Payoff Scenarios
This is where most calculators stop too soon. They show you one scenario. You need to see three.
Scenario A: Pure Avalanche (No Consolidation)
Apply the $715 monthly surplus to CC1 first. Minimum payments on everything else. When CC1 is gone, cascade that $168 minimum + $715 into CC2. And so on.
With a $3,100 lump sum applied to CC1 immediately:
- CC1 balance drops to $5,300 at 24.99%
- CC1 payoff timeline: approximately 8 months
- Cascade then hits CC2, clearing it around month 14
- Personal loan cleared around month 28
- Full debt freedom: approximately month 50
- Total interest paid: approximately $14,800
Scenario B: Balance Transfer (Transfer CC1 + CC2)
Most competitive 0% balance transfer offers in April 2026 run 18–21 months at 0% APR with a 3%–5% transfer fee (Citi and Wells Fargo are both in this range). Let's use 3% fee, 18-month 0% promo.
Transferable balance: $8,400 + $6,300 = $14,700 Transfer fee: $14,700 × 3% = $441 Net balance on new card: $15,141
Interest saved during 18-month promo (vs paying 24.99% and 21.49%): approximately $3,940 Net benefit after fee: $3,499
With the $715 surplus now going entirely toward the transfer card balance (since minimums on CC1 and CC2 are "freed up"):
- Transfer card cleared in approximately month 17 — just inside the promo window
- Cascade then moves to personal loan
- Full payoff: approximately month 48
- Total interest paid: approximately $11,300
Balance transfer saves ~$3,500 vs pure avalanche — but it requires a credit score above ~720, and it requires discipline: the two freed-up cards must stay at $0. Every study on revolving credit behavior (including the behavioral finance research behind the NerdWallet April debt Q&A) shows that 40%+ of consumers re-accumulate on freed cards within 18 months. If you spend even $2,000 on those freed cards, you've erased most of the savings.
Scenario C: HELOC Consolidation (If You're a Homeowner)
If you have home equity, the math shifts again. Current HELOC rates in April 2026 are running approximately 8.25%–9.0% (prime rate 7.5% + typical margins of 0.75%–1.5%). Mortgage rates dipped slightly today per NerdWallet's April 17 daily rate tracker, but HELOC rates are prime-linked, not mortgage-linked — they move with the Fed, not with 10-year Treasury yields.
Consolidate CC1 + CC2 + personal loan: $27,500 at 8.5%
Weighted average rate on those three accounts before consolidation: ($8,400 × 24.99% + $6,300 × 21.49% + $12,800 × 11.99%) / $27,500 = ($2,099 + $1,354 + $1,535) / $27,500 = 18.1% weighted APR
Monthly interest before HELOC: $27,500 × 18.1% / 12 = $414/month Monthly interest after HELOC: $27,500 × 8.5% / 12 = $195/month Monthly savings: $219/month
HELOC closing costs: typically $500–$800. At $625, break-even is $625 / $219 = 2.85 months. After that, every month you're $219 ahead.
Total interest saved vs avalanche over the full payoff period: approximately $6,200 Full payoff timeline: approximately month 46 Total interest paid: approximately $8,600
This is the kind of three-scenario analysis that Kovarino runs for you automatically — because building this spreadsheet correctly for your actual balances and rates takes hours, and one wrong formula erases the insight.
Step 3: Calculate the Break-Even for Each Non-Avalanche Option
Before committing to balance transfer or HELOC, you need to know when each strategy "earns back" its upfront cost.
Balance transfer break-even formula:
Break-even (months) = Transfer fee / (Monthly interest at original rate on transferred balance) = $441 / ($14,700 × weighted rate / 12) = $441 / ($14,700 × 23.4% / 12) = $441 / $286.65 = 1.54 months
Translation: after 2 months, the balance transfer has paid for itself. The risk isn't the math — it's behavior over the next 18 months.
HELOC break-even formula:
Break-even (months) = Closing costs / Monthly interest savings = $625 / $219 = 2.85 months
Translation: if you close the HELOC and don't default or sell the house within 3 months, you come out ahead financially. The risk is different here: you've converted unsecured debt to secured debt. Default on a credit card and you take a credit hit. Default on a HELOC and you can lose the house.
For a deeper breakdown of how these break-even calculations play out with larger debt totals, the analysis in Avalanche vs. Balance Transfer vs. HELOC on $74,200 in Mixed Debt walks through the same step-by-step formula on a different scenario.
Step 4: Apply the $3,100 Tax Refund Optimally
Back to the original question. Where does the $3,100 go?
Under Scenario A (avalanche): Apply directly to CC1. Cuts balance from $8,400 to $5,300. Annual interest savings: $3,100 × 24.99% = $775/year. Shortens payoff by approximately 4 months.
Under Scenario B (balance transfer): Use $441 of the refund to pay the transfer fee, deploy the remaining $2,659 immediately against the transfer card balance. You're already at break-even day one, and your 18-month clock starts with a $12,482 balance instead of $15,141.
Under Scenario C (HELOC): Use $625 for closing costs, apply $2,475 to the highest-rate remaining debt (auto loan doesn't make sense here — the HELOC already cleaned out the high-rate accounts). Actually redirect to auto loan principal: $2,475 applied at 7.24% saves $179/year in interest and accelerates your full payoff.
The right answer depends on which scenario your situation supports — and that's entirely determined by your credit score, home equity position, behavioral track record with revolving credit, and income stability.
You can model your specific refund deployment at Kovarino — plug in your actual balances and rates to see which allocation generates the highest dollar return.
The Comparison Table
| Strategy | Total Interest | Months to Freedom | Upfront Cost | Key Risk |
|---|---|---|---|---|
| Pure Avalanche | ~$14,800 | ~50 | $0 | Time, discipline |
| Balance Transfer | ~$11,300 | ~48 | $441 | Behavior, credit score |
| HELOC Consolidation | ~$8,600 | ~46 | $625 | Secured debt, variable rate |
The HELOC wins on pure math by $6,200 over the avalanche and $2,700 over the balance transfer. But it requires home equity, adds secured-debt risk, and is exposed to rising rates (HELOC rates could climb if the Fed resumes hiking).
The balance transfer is the middle path — better math than the avalanche, lower risk than the HELOC, but requires credit access and behavioral discipline.
The avalanche wins if you don't have home equity, can't qualify for a 0% card, or have a history of re-accumulating on freed cards. It's the strategy that depends entirely on you, not on external lenders. For a look at how the avalanche vs. snowball decision alone can shift outcomes on similar debt loads, see Avalanche vs. Snowball: The $12,847 Difference on $56,900 in Debt.
What These Numbers Don't Tell You
The $55,700 scenario above is worked from reasonable current-rate assumptions. Your numbers will differ based on:
- Your actual APRs (especially if you've had a rate increase since opening the account)
- Your credit score and whether you can actually qualify for competitive balance transfer offers
- Whether you have accessible home equity at a HELOC rate under 9%
- Your tax situation (the student loan deduction phases out significantly above $70,000 MAGI)
- Whether you're the type of person who closes a freed credit card or treats it as "available balance"
That last variable — the behavioral one — has been studied extensively. The behavioral cost gap between optimal math and how people actually execute can be larger than the gap between strategies. The post on the $59,200 behavioral cost gap quantifies exactly what that execution failure costs in dollar terms.
Run These 4 Steps on Your Actual Numbers
The formula is simple: calculate effective APRs → model three scenarios → calculate break-even for each consolidation option → deploy lump sums optimally. The complexity is in doing it correctly with your real balances, your real rates, and your real situation.
Most people spend more time researching a $400 appliance than they do calculating a $6,200 debt payoff decision. The math isn't hard once it's set up — it's just tedious enough that people skip it and default to a rule of thumb.
Kovarino runs this analysis for you — all four steps, across your specific debt mix, modeled against current rate environments. The output isn't a generic recommendation. It's your numbers, your sequence, your break-even points.
The difference between guessing and calculating is $6,200. That's worth 15 minutes.
Sources
- The Shockingly Simple Math Behind Social Security — Mr. Money Mustache
- Your Top April Questions: Tax Refunds, Debt and More — NerdWallet
- Mortgage Rates Today, Friday, April 17: A Little Lower — NerdWallet
- Coffee Shop Insurance: What You Need, Best Companies — NerdWallet
- The Guide to Wells Fargo Transfer Partners — NerdWallet