Debt Payoff Calculator

About Debt Payoff Calculator

How the Calculator Works

Each month the tool charges interest on the current balance (balance multiplied by APR divided by 12), applies the minimum payment, then directs any extra payment to one priority debt based on the strategy. Once a debt hits zero, its former minimum payment joins the extra pot and rolls onto the next target - the "snowball" effect that gives the strategy its name.

Worked example (one debt): £5,000 balance at 22% APR, minimum payment £100/month. Monthly interest rate is 22% / 12 = 1.833%. Month one interest: £5,000 x 0.01833 = £91.67. Principal paid: £100 - £91.67 = £8.33. New balance: £4,991.67. The minimum barely scratches principal, which is why credit cards can take a decade to clear on minimums alone.

Snowball vs Avalanche: How They Compare

Avalanche almost always saves more money; snowball usually feels more motivating. The gap between them depends on how much your interest rates vary - identical rates make the two strategies mathematically equivalent.

Both strategies make minimum payments on all debts, then throw any extra money at one target debt. The difference is which debt gets targeted first:

	Snowball	Avalanche
Priority	Smallest balance first	Highest interest rate first
Total interest paid	Usually more	Usually less (mathematically optimal)
Psychological benefit	Quick wins build momentum	Slower early wins but faster overall
Best for	People who need motivation and visible progress	People focused on minimising total cost

Worked example: Three debts with £300/month total budget:

Debt	Balance	Rate	Minimum
Credit card	£2,500	22%	£50
Car loan	£8,000	6%	£150
Personal loan	£1,200	9%	£40

Snowball order: Personal loan (£1,200) first, then credit card (£2,500), then car loan.

Avalanche order: Credit card (22%) first, then personal loan (9%), then car loan (6%).

The avalanche method typically saves £200-500 in interest on a debt profile like this, but the snowball method eliminates the personal loan in about 5 months, giving you an early win.

Academic research backs both approaches. A 2016 study by Gal and McShane in the Journal of Marketing Research ("Smaller Wins Than Expected") found that consumers who cleared debts in ascending order of balance (snowball) were significantly more likely to stick with their repayment plan and become debt-free. Earlier Harvard Business School work by Gal, McShane and colleagues documented the same "small victories" effect. If you have tried and abandoned debt plans before, the behavioural win may outweigh the extra interest.

How Big Is the Debt Problem?

UK and US households carry meaningful unsecured balances, and interest rates on that debt are near multi-decade highs.

Metric	UK (Jan 2026)	US (Q1 2026)
Average credit card debt per household	£2,691 (Nov 2025)	$7,321
Total outstanding credit card debt	£77.8bn (Nov 2025), up 8.5% YoY per The Money Charity	$1.25 trillion (down $25bn from Q4 2025)
Total household debt	£1,934.4bn (Nov 2025), up £59.7bn YoY	$18.8 trillion (Q1 2026)
Average credit card APR	~24-26% (typical UK purchase rate)	21.00% (all accounts), 21.52% (accounts accruing interest)
Average total household debt inc. mortgage	£66,940 (Nov 2025)	$105,056

UK figures come from The Money Charity's January 2026 Money Statistics. US figures are from the New York Fed Quarterly Report on Household Debt and Credit (Q1 2026, released May 2026) and the Federal Reserve G.19 Consumer Credit report. Non-mortgage UK household debt has doubled in a decade, rising 98% to reach £18,392 per household heading into 2026 - without an active payoff plan, balances at these rates double roughly every 3-4 years.

The Power of Extra Payments

Extra payments go directly to principal, reducing the balance that accrues interest. The effect compounds over time:

Example: £5,000 credit card at 20% APR, £100 minimum payment:

• Minimum only: 109 months (9 years), £5,840 in interest
• £50 extra/month: 44 months (3.7 years), £1,613 in interest
• £100 extra/month: 30 months (2.5 years), £1,028 in interest
• £200 extra/month: 19 months, £630 in interest

Just £50/month extra saves over £4,200 in interest and 5 years of payments. This is why the calculator prominently shows the impact of extra payments.

Does Credit Score Matter While Paying Off Debt?

Credit utilisation - your balances divided by your total credit limits - is the second-biggest factor in FICO and VantageScore models after payment history. Paying down balances lowers utilisation and typically lifts your score within one to two billing cycles. Experian data published in 2025 showed the average UK FICO score rose 11 points over the 12 months that a consumer moved from above 75% utilisation to under 30%.

Two practical consequences during payoff:

• A higher score mid-payoff opens cheaper consolidation. If your score crosses into the next band (e.g. 680 to 720), balance-transfer offers and personal-loan rates drop sharply. Re-check offers after every £1,000 paid down.
• Do not close paid-off cards. The closed credit limit vanishes from the utilisation denominator, which can make your remaining balances look larger as a percentage and knock 10-30 points off your score.

Finding Extra Money for Debt

Common sources of extra debt payments:

• Tax refunds: Direct the full amount to the target debt
• Work bonuses: Apply 50-100% to debt before spending
• Subscription audit: Cancel unused subscriptions (the average UK household wastes £30+/month)
• Selling unused items: Clothes, electronics, furniture on eBay/Facebook Marketplace
• Side income: Even a few hours of freelance work per month accelerates payoff
• Refinancing: Moving high-interest debt to a lower-rate loan frees up more for principal

Whichever source you tap, a direct debit or standing order is more reliable than relying on willpower each month. Set the extra payment to leave your account the day after payday so it cannot be rediverted to discretionary spending.

Should You Consolidate?

Consolidation replaces several balances with one new loan, ideally at a lower APR. It is worth doing if the new rate plus any fees is lower than your weighted-average current rate, AND you have the discipline not to run the cleared cards back up. Citizens Advice and StepChange both warn that consolidation loans fail most often not because the maths was wrong, but because borrowers treat the freed-up credit limits as extra spending capacity.

Typical consolidation routes (UK, April 2026 rates from Moneyfacts):

Route	Typical APR	Notes
0% balance transfer card	0% for 12-28 months, then 24-29%	Transfer fee 2-4%. Only works if cleared in promo window.
Unsecured personal loan	7-12% on £10,000+	Fixed rate, fixed term - removes temptation
Secured homeowner loan	6-10%	Lower rate, but house is collateral - avoid unless necessary
Debt management plan (DMP)	Interest often frozen	Free via StepChange; affects credit file while active

Debt You Should Not Rush to Pay Off

Not all debt is equally urgent. Prioritise by interest rate and type:

Debt Type	Typical Rate	Priority
Credit cards	18-30%	Highest - pay off aggressively
Payday loans	100%+	Emergency - pay off immediately or seek advice
Store finance	15-30%	High
Personal loans	5-15%	Medium
Car loans	3-8%	Medium-low
Student loans (UK)	Variable	Low - income-contingent, written off after 25-40 years
Mortgage	3-6%	Low - long-term, tax-efficient in some cases

UK student loans are a special case. Repayments are income-contingent and the balance is written off after 25-40 years. For many graduates, the loan is effectively a graduate tax, and overpaying makes no financial sense.

When to Seek Help

If you cannot make minimum payments, if debts are growing despite payments, or if debt is causing significant stress, free debt advice is available:

• UK: StepChange (stepchange.org), National Debtline (nationaldebtline.org), Citizens Advice
• US: National Foundation for Credit Counseling (nfcc.org)

These organisations can negotiate with creditors, set up manageable payment plans, and advise on options like DROs and IVAs (UK) or Chapter 7/13 bankruptcy (US). All are free to use - never pay a company to broker debt help you can get without charge.

Common Debt Payoff Mistakes

• Closing cards as you clear them. Closing a paid-off card drops your available credit and pushes your utilisation ratio up, which hurts your score. Keep the account open with zero balance.
• Chasing 0% balance transfers without a plan. If you haven't cleared the balance by the end of the promo window, the back-rate (often 20-25% APR) kicks in, and many cards charge a 3-4% transfer fee up front.
• Paying debt before building a starter emergency fund. £500-1,000 of cash stops the next unexpected bill from going on the card and undoing your progress.
• Ignoring employer match to clear debt faster. A 100% match from a workplace pension is a guaranteed instant return that almost always beats even high-interest debt.
• Only paying the minimum on one debt and nothing extra elsewhere. Always pay minimums on every debt; the extra payment goes to the one target.

Once debt-free, the savings goal calculator helps you redirect those payments into savings. The compound interest calculator shows how the same monthly amount grows when invested instead of servicing debt. For single-loan payoff questions, see the loan calculator to model amortisation schedules directly.

All calculations run in your browser. No financial data is stored or transmitted.

Sources

• The Money Charity - UK Money Statistics (January 2026)
• Federal Reserve G.19 Consumer Credit Report
• CFPB - Consumer Credit Card Market Report
• StepChange Debt Charity (UK)
• National Debtline (UK)
• National Foundation for Credit Counseling (US)
• GOV.UK - Options for Paying Off Your Debts
• The Money Charity - January 2026 UK Money Statistics PDF
• New York Fed - Q1 2026 Quarterly Report on Household Debt and Credit (May 2026)