How DebtRiot Calculates Your UK Debt Payoff Plan (Methodology)

What the planner does

• Builds a month-by-month schedule from today to debt-free

• Supports Snowball, Avalanche, Hybrid (switch after N) and Custom ordering

• Handles UK overdrafts (EAR) and 0% promotional periods

• Lets you set your payday, then provides printable calendars

• Shows milestones (each debt cleared, debt-free date)

• Optional What-If: add a monthly extra to see time & interest saved

Inputs (what you enter) & how the budget is calculated

1) Your monthly numbers (entered once):

• Income (take-home, per month)

• Essentials (per month): rent/mortgage, bills, food, transport, etc.

• Emergency fund (optional, per month)

The planner calculates your debt budget automatically:
Debt budget = Income − Essentials − Emergency fund

2) Your debts (add each one):

• Name (e.g., “Barclaycard”)

• Balance today (£)

• Rate — APR for cards/loans, EAR for overdrafts

• Minimum payment (£) — one fixed amount per month

• Optional promos: 0% promo months left and revert APR (post-promo rate)

3) Your preferences (entered once):

• Strategy: Snowball, Avalanche, Hybrid (switch after N) or Custom

• Payday: the day of the month you usually pay towards debts

How the monthly allocation works

Interest modelling (APR vs EAR)

• Cards/loans: we use your APR and apply a monthly rate to the remaining balance after that month’s payments.

• Overdrafts: UK overdrafts are quoted as EAR. We convert EAR to an equivalent monthly rate for planning.

• Fees: add any one-off fees (e.g., balance-transfer fee) to the balance if you want them reflected.

We model months discretely. Daily accrual nuances are approximated by the monthly rate - accurate enough for planning and a clear printable schedule.

Payoff ordering (four methods)

Snowball — smallest balance first
After minimums, leftover budget targets the smallest remaining balance.
Why choose Snowball? Quick wins → easier to stick with.

Avalanche — highest APR/EAR first
After minimums, leftover budget targets the highest interest rate debt.
Why choose Avalanche? Often minimises total interest.

Hybrid — switch after N months
Run one method first, then automatically switch to the other after N months. You choose both the starting method and N (common choices: 3–6 months).

Custom — your order
Choose the exact payoff order (e.g., clear a specific lender first to free a limit).

0% promotional periods (balance transfers & offers)

• Default: during a 0% promo, that debt gets minimum payments only. When the promo ends, the revert APR applies and the planner re-prioritises automatically.

• Option — prioritise early: tick “Prioritise 0% promo debts early” to clear a promo balance before it ends (e.g., to free credit).

• Option — permanent 0%: tick “Include permanent 0% in priority” to treat truly 0% balances like normal debts.

Tip: set promo months left accurately and enter the post-promo APR so dates and interest totals reflect reality.

Overdrafts (EAR) — how we handle them

• Add overdrafts using EAR.

• Overdrafts are included like other debts; under Avalanche, they’re typically targeted early due to the effective rate.

• If fees apply, include them in the balance you enter.

Payment timing, payday & calendars

• Choose your payday; the plan assumes one payment per month on/near this day.

• The PDF includes calendars. The year view shows your payday note at the bottom

• Monthly schedule pages show payment amounts and running balances.
  
  
  
  
  
  
  
  
  
  
  

  
  
  
  
  
  
  
  
  Example pages from a personalised plan (sample numbers): summary with debt-free date and milestones, plus calendar page (year view). Your chosen payday is shown once at the bottom (e.g., “Pay on the 28th”). Running balances appear on the monthly schedule pages.
  

  Rounding, micro-balances & edge cases

• Payments round to pennies.

• When a balance is within a few pounds of clearing, we pay the final residual and re-allocate any small remainder to the next debt that month.

• If your budget is below total minimums, the planner flags a shortfall.

Assumptions & limitations

• Self-guided planning tool; not regulated financial advice.

• You maintain your inputs (balances/rates) to keep results accurate.

• Variable/penalty rates and missed-payment fees aren’t predicted.

• Interest is modelled monthly; daily compounding effects are approximated.

Privacy & data

• Anonymous by design: inputs run in your browser; we don’t save your numbers.

• No account required; the PDF is generated from your current inputs.