Loan Tenure Calculator
How long a loan takes to clear at a given payment. If the payment does not cover the first month's interest, the tool says so rather than returning an impossible number.
Also called: how long to pay off loan, loan payoff time.
Paying $500 a month clears this loan in 5 years 2 months. Total interest: $5,511.15.
An estimate, not an offer or a guarantee. Projected returns assume the rate you entered holds for the whole term, which no market does.
amortization_schedule
| Month | Payment | Interest | Principal | Balance |
|---|---|---|---|---|
| 1 | $500 | $167 | $333 | $24,667 |
| 2 | $500 | $164 | $336 | $24,331 |
| 3 | $500 | $162 | $338 | $23,993 |
| 4 | $500 | $160 | $340 | $23,653 |
| 5 | $500 | $158 | $342 | $23,311 |
| 6 | $500 | $155 | $345 | $22,966 |
| 7 | $500 | $153 | $347 | $22,619 |
| 8 | $500 | $151 | $349 | $22,270 |
| 9 | $500 | $148 | $352 | $21,919 |
| 10 | $500 | $146 | $354 | $21,565 |
| 11 | $500 | $144 | $356 | $21,209 |
| 12 | $500 | $141 | $359 | $20,850 |
This is what the calculation gives for the numbers you entered. It is an estimate, not advice, and it knows nothing about your situation beyond those numbers. Rules for United States change on a published schedule; the effective date is shown on every rule-based tool.
How this is calculated
The annuity relation solved for n, which needs a logarithm because n sits in an exponent. The interesting part is the boundary: when the payment is less than or equal to the interest accruing each month, the balance never falls and there is no n that satisfies the equation. Most calculators return a negative number or NaN there. This one explains the situation.
n = -ln(1 - i*P/E) / ln(1+i)- E
- The equal periodic instalment (currency)
- P
- Principal: the amount borrowed (currency)
- i
- Monthly interest rate = annual rate ÷ 12 ÷ 100 (decimal)
- n
- Total number of monthly instalments (months)
Full derivation: The annuity payment, derived from scratch
Method and limits
What it assumes
- Interest compounds monthly on the reducing balance.
- The rate stays fixed for the whole term. Floating-rate loans reset periodically.
- Processing fees, insurance and statutory charges are excluded.
What it deliberately does not model
- Does not model rate resets on floating-rate loans. Most lenders hold the instalment steady and extend the term instead, so a rate rise can add years without changing what leaves your account each month.
- Does not include property insurance, maintenance or association dues, or any lender fee.
- Assumes every instalment is paid in full and on time.
Formula version 1.0.0 · definition 1.0.0 · United States · Report a problem with this calculator
Frequently asked questions
- Does a longer term cost more even at the same rate?
- Substantially. The instalment falls and the total interest rises, because the balance is outstanding for longer. Ten extra years on a 20-year home loan cuts the monthly payment by about a tenth and adds more than half again to the interest.
- Why does the term barely move when I increase the payment a lot?
- Because the relationship is logarithmic, not linear. Once the payment comfortably exceeds the interest, further increases shorten the tail of the loan where little interest is left to save.