Complete guide
Debt Payoff Calculator: formula, worked example and interpretation
Model a combined debt balance with a weighted APR, monthly payment and optional extra payment. Enter the known values and the result updates instantly with an auditable breakdown.
What the Debt Payoff Calculator answers
Model a combined debt balance with a weighted APR, monthly payment and optional extra payment.
Use the breakdown to compare the result with the source values before making a decision.
Formula and variables
The calculation uses weighted APR=Σ(balance×APR)/Σbalance; payoff iterates monthly. Every variable comes directly from a labeled field.
weighted APR=Σ(balance×APR)/Σbalance; payoff iterates monthlyWorked example
Two debts are combined for a planning view, then the entered payment is applied until the balance reaches zero.
Changing any field recalculates the result immediately, so nearby scenarios can be compared without reloading the page.
How to use the result
Treat the result as a planning value and compare it with the detailed rows shown beside it.
Keep units and time periods consistent. Use the share or PDF action to preserve the exact assumptions.
Assumptions and scope
A true snowball or avalanche schedule depends on each account's minimum payment and allocation order; this view uses one weighted-rate balance.
The calculator exposes its assumptions instead of filling missing facts with hidden estimates.
Accuracy checks
Confirm the units, dates, rates and source figures before relying on the output.
Round only the displayed answer; Calculator24 keeps full JavaScript precision for intermediate arithmetic and exported values.
Input and output checklist
| Item | What to enter or review |
|---|---|
| Inputs | Debt A balance ($), Debt A APR (%), Debt B balance ($), Debt B APR (%), Total monthly payment ($), Extra monthly payment ($) |
| Equation | weighted APR=Σ(balance×APR)/Σbalance; payoff iterates monthly |
| Example | Two debts are combined for a planning view, then the entered payment is applied until the balance reaches zero. |
| Limit | A true snowball or avalanche schedule depends on each account's minimum payment and allocation order; this view uses one weighted-rate balance. |
Frequently asked questions
What does this Debt Payoff Calculator calculate?
Model a combined debt balance with a weighted APR, monthly payment and optional extra payment.
Which formula does it use?
weighted APR=Σ(balance×APR)/Σbalance; payoff iterates monthly
Does the result update while I type?
Yes. Valid changes recalculate after a short delay and the previous result is not substituted for invalid input.
Which assumptions should I check?
Check units, rates, dates and every source value shown in the form.
Is the result exact?
A true snowball or avalanche schedule depends on each account's minimum payment and allocation order; this view uses one weighted-rate balance.
Can I save or share the calculation?
Yes. Copy, Share, WhatsApp, PDF/Print, CSV, comparison and parameterized-link actions are available.
What to keep in mind
A true snowball or avalanche schedule depends on each account's minimum payment and allocation order; this view uses one weighted-rate balance.
Results display up to 8 decimal places; exported numbers preserve calculation precision. This is a calculation summary, not an official certificate.