Debt Spiral Risk Calculator

A debt spiral happens when interest and minimum payments take more out of monthly income than the budget can absorb, so the balance climbs even while payments are being made. The risk rises when minimum payments crowd out essentials and additional borrowing fills the shortfall.

This calculator produces a 0-100 risk score from three signals: how much of monthly take-home income goes to minimum payments, how large total debt is relative to annual income, and whether what's left after fixed costs covers the minimums. The score is a weighted composite — payment-to-income carries 50% of the weight, total debt as a share of annual income contributes 30%, and the coverage gap accounts for the remaining 20%.

How to use it

Enter total outstanding debt, monthly take-home income (after tax), the sum of minimum payments due across all debts, and what's left over each month after fixed costs (rent, utilities, food, transport). Adjust any input and the score recalculates instantly. The currency selector at the top of the calculator changes formatting throughout — the math and the score are currency-neutral, so the same ratios produce the same score regardless of currency.

Reading the inputs

Total Debt covers credit cards, personal loans, store cards, BNPL balances, and other unsecured borrowing. Mortgages and student loans are usually tracked separately because their structure and risk profile differ. Monthly Take-Home Income is what lands in the account after tax and pension contributions. Total Minimum Payments is the sum of the smallest amounts due each month to keep all accounts current. Monthly Discretionary Income is what remains after rent, bills, food, and transport — the buffer that has to absorb minimums.

How the saturation anchors work

Each component score scales 0-100 against an anchor. The PTI score saturates when minimum payments equal half of monthly take-home — at that point monthly affordability is gone, so the score caps at 100. The DTI score saturates when total debt equals one full year of take-home income — beyond that the score doesn't keep climbing because the picture is already extreme. The coverage score is zero when discretionary income meets or exceeds minimums and rises smoothly as the gap widens, saturating at no discretionary income at all. Modest values (PTI in the 20s, debt at 70% of annual income) produce mid-range component scores rather than maxing anything out.

Worked example

Picture a household with total debt around 8.5× monthly take-home, payment-to-income at 22.9%, debt at 71% of annual take-home, and discretionary income covering 87.5% of minimums (so the coverage check fails by a small margin). Concretely that is total debt 30,000, monthly take-home 3,500, minimum payments 800, discretionary income 700 — currency follows the selector. The score lands at 47/100 — Moderate Risk. The breakdown: PTI score around 46 (22.9 ÷ 50 × 100), DTI score 71 (debt sits at 71% of annual take-home), coverage score around 12.5 (small gap). After the 50/30/20 weighting, debt size and payment burden are the main drivers; the coverage gap adds a few points but isn't the largest factor.

Score brackets

0-29 is Low Risk: payments are small relative to income and debt is manageable. 30-49 is Moderate Risk: at least one component is putting pressure on the budget. 50-69 is High Risk: multiple components are working against the budget at once. 70+ is Critical Risk: the math indicates the balance is more likely to grow than shrink without changes to income, expenses, or the structure of the debt itself. The bracket boundaries are the tool's own calibration, not external regulatory thresholds.

What this calculator doesn't capture

The score is a snapshot of three ratios. It does not include the interest rate on individual debts, the difference between secured and unsecured borrowing, missed-payment fees, balance transfer offers, or income that isn't part of monthly take-home. It also doesn't separate debt that's actively reducing (a personal loan amortising on schedule) from debt that's growing (revolving credit at minimum payments). the figure functions as a starting indicator, not a complete picture.

If the score is high

A high score points to three options that can be considered separately: reducing the cost of debt (refinancing, balance transfers, consolidation), reducing the size of debt (extra principal payments where the budget allows), and seeking structured help. Most countries have free, independent debt advice services run by charities or government-backed bodies; commercial debt-management services typically charge fees. Local consumer-protection regulators usually publish lists of authorised non-profit options.