How close are you to the spiral?

A debt spiral is when interest and fees grow faster than you can pay down, making the balance climb despite making payments. It usually starts when minimum payments consume more than 30% of income, or when discretionary income doesn't cover minimums and further debt fills the gap.

This calculator scores your spiral risk on 0-100 based on debt-to-income ratio, payment-to-income ratio, and whether discretionary income covers minimum payments. Under 40 is Low Risk, 40-70 is Moderate/High Risk, 70+ is Critical Risk requiring immediate action.

Critical risk means talking to a debt advisor (StepChange, Citizens Advice, National Debtline) this week, not next month. At that level, interest compounds faster than repayment is possible without structural changes - debt management plans, IVAs, or in extreme cases bankruptcy. Earlier intervention prevents worse outcomes.

Run it with sensible defaults

Using total debt of 30,000, monthly take-home income of 3,500, total minimum payments of 800, monthly discretionary income of 700, the calculation works out to 60/100. Nudge the inputs toward your own situation and the output recalculates instantly. The defaults are meant as a starting point, not a recommendation.

The levers in this calculation

The inputs — Total Debt, Monthly Take-Home Income, Total Minimum Payments, and Monthly Discretionary Income — do not pull with equal force. Not every input has equal weight. Flip one at a time toward extreme values to feel which ones move the needle most for your situation.

How the math works

Risk score based on payment-to-income ratio (main driver) with modifier if discretionary income insufficient. Thresholds: 15% = Low, 25% = Moderate, 40% = High, above = Critical. The working is transparent — you can verify every step yourself in the formula section below. No black box, no opaque "proprietary model".

Reading the output honestly

The payoff date assumes every payment lands on time and at the amount you entered. In reality, months with unexpected expenses happen. Treat the figure as the best-case timeline and add a buffer for life if you want a realistic target.

What this doesn't capture

Real payoff journeys include missed payments, fee changes, balance transfers, and promotional rates that reset. The calculation assumes a steady plan; reality is rarely that clean. Use the figure as the best-case plan against which actual progress gets measured.