AtlasCalcsUtility Calculation Suite
2026-09-21 7 min read

Personal Loan Amortization Calculator

The full period-by-period amortisation schedule for a personal loan. Live calculator with worked steps, charts and a full amortisation schedule.

Calculator

Loan Amount Help
$

The amount you borrow, before fees are deducted.

Annual Interest Rate(%)
%
Loan Term(years)
years
Extra Months(months)
months
Payment Frequency
Extra Payment Each Period
$
One-Time Extra Payment
$
One-Time Payment Made At Payment #
Advanced options (1)
First Payment Date

This personal loans calculator runs on the standard amortisation model: interest is charged on the outstanding balance each month, and anything extra you enter is applied to principal immediately.

Amortization schedule

Balance Interest Payment
View:
MonthInterestPrincipalEnding Balance
1$143.75$247.59$14,752.41
2$141.38$249.96$14,502.46
3$138.98$252.35$14,250.10
4$136.56$254.77$13,995.33
5$134.12$257.21$13,738.12
6$131.66$259.68$13,478.44
7$129.17$262.17$13,216.27
8$126.66$264.68$12,951.59
9$124.12$267.22$12,684.38
10$121.56$269.78$12,414.60
11$118.97$272.36$12,142.24
12$116.36$274.97$11,867.27
End of year 1
13$113.73$277.61$11,589.66
14$111.07$280.27$11,309.39
15$108.38$282.95$11,026.44
16$105.67$285.67$10,740.78
17$102.93$288.40$10,452.37
18$100.17$291.17$10,161.21
19$97.38$293.96$9,867.25
20$94.56$296.77$9,570.48
21$91.72$299.62$9,270.86
22$88.85$302.49$8,968.37
23$85.95$305.39$8,662.98
24$83.02$308.31$8,354.66
End of year 2
25$80.07$311.27$8,043.40
26$77.08$314.25$7,729.14
27$74.07$317.26$7,411.88
28$71.03$320.30$7,091.57
29$67.96$323.37$6,768.20
30$64.86$326.47$6,441.73
31$61.73$329.60$6,112.12
32$58.57$332.76$5,779.36
33$55.39$335.95$5,443.41
34$52.17$339.17$5,104.25
35$48.92$342.42$4,761.83
36$45.63$345.70$4,416.12
End of year 3
37$42.32$349.01$4,067.11
38$38.98$352.36$3,714.75
39$35.60$355.74$3,359.02
40$32.19$359.14$2,999.87
41$28.75$362.59$2,637.29
42$25.27$366.06$2,271.22
43$21.77$369.57$1,901.66
44$18.22$373.11$1,528.54
45$14.65$376.69$1,151.86
46$11.04$380.30$771.56
47$7.39$383.94$387.62
48$3.71$387.62$0.00

Results

Optimal

Scheduled Payment

$391.34/month

Level payment for 48 monthly payments.

Total Interest

$3,784

Loan Amount

$15,000

Annual Interest Rate

11.50%

Total of Payments

$18,784

Number of Payments

48

4 years

Interest in Payment 1

$143.75

Principal in Payment 1

$247.59

Final Payment

$391

Final Payment Date

48 payments from today

Live results update as you type — currently showing scheduled payment of $391.34 /month on 12 payments a year. Replace the defaults with your own quote for an exact comparison.

Visualizations

Interest vs Principal by Year (interest shown)

1,563Y1
1,183Y2
757Y3
280Y4

Total Cost Split

Principal80%
Interest20%

Outstanding Balance by Year

Formula

Each period the balance grows by the interest due and shrinks by the payment. The difference is the principal reduction that drives the next row of the schedule.

Payment(k) = Balance(k−1) × i + Principal(k)

Alternative Form

Balance(k) = Balance(k−1) × (1 + i) − Payment

Variables

SymbolNameUnitDescription
PPayment per periodcurrencyLevel payment that fully amortises the balance
ALoan amount (principal)currencyAmount borrowed before any financed fees
iPeriodic interest ratedecimalAnnual rate ÷ payments per year
nNumber of paymentscountTerm in years × payments per year

Explanation

This is the period-by-period breakdown of every payment into interest, principal and remaining balance.

Step-by-Step Calculation

Follow each step to understand how the result is calculated from your inputs.

Step 1

Convert the annual rate to a per-month rate: 11.50% ÷ 12 periods per year.

i = APR ÷ payments per year
Annual rate:11.50%
Periods per year:12
Intermediate: i = 0.009583
Result: 0.9583% per month
Step 2

Count the payments: 48 months at monthly frequency.

n = years × payments per year
Term:4 years
Payments per year:12
Result: 48 payments
Step 3

Apply the amortising payment formula to the loan amount.

P = A × i ÷ (1 − (1 + i)^−n)
Loan amount:$15,000
Per-period rate:0.9583%
Payments:48
Intermediate: P = $15,000.00 × 0.009583 ÷ (1 − (1 + 0.009583)^−48)
Result: $391.34 /month
Step 4

Multiply the payment by the number of payments and subtract the amount borrowed.

Total interest = payment × n − principal
Payment:$391.34 × 48
Intermediate: $18,784.09 − $15,000
Result: $3,784 total interest
Final Answer
$391.34

Worked Examples

See how the calculator works with different scenarios.

Scenario

The personal loan amortization calculator run on the values above, showing the full calculation path rather than only the answer.

Inputs

Amount:15000
Rate:11.5
Years:4
Frequency:monthly (12 per year)

Calculation

1. Convert the annual rate to a per-month rate: 11.50% ÷ 12 periods per year. → 0.9583% per month 2. Count the payments: 48 months at monthly frequency. → 48 payments 3. Apply the amortising payment formula to the loan amount. → $391.34 /month 4. Multiply the payment by the number of payments and subtract the amount borrowed. → $3,784 total interest

Result

Scheduled Payment: $391.34 /month

Interpretation

Level payment $391.34 /month; period-1 interest $143.75 leaves $247.59 of principal reduction. Finance charge $3,784.

Understanding Your Result

Your Result: Scheduled Payment: $391.34 /month

What This Means

This is the period-by-period breakdown of every payment into interest, principal and remaining balance.

Why It Matters

Level payment $391.34 /month; period-1 interest $143.75 leaves $247.59 of principal reduction. Finance charge $3,784.

Professional Interpretation

Level payment $391.34 /month; period-1 interest $143.75 leaves $247.59 of principal reduction. Finance charge $3,784.

How this is calculated

Each period the balance grows by the interest due and shrinks by the payment. The difference is the principal reduction that drives the next row of the schedule.

What drives the result

Each payment is split between the interest charged on the outstanding balance and the principal that reduces it. Because interest is calculated on whatever is still owed, the interest share is highest at the start and falls every period. That is why early extra payments save far more than the same dollars paid later in the term.

Recommendations

  • •The interest share falls every period — the crossover point (where principal beats interest) is the real half-way mark.
  • •Use the annual view for loans longer than five years and the monthly view to check a specific payment.

Educational Content

Introduction

Instalment credit is priced with one equation: a level payment that repays principal and interest over a fixed number of periods. Every figure on this page — payment, balance, payoff date, interest saved — is derived from that single relationship, which is why changing any one input shifts all of them.

Concept Explanation

Each payment is split between the interest charged on the outstanding balance and the principal that reduces it. Because interest is calculated on whatever is still owed, the interest share is highest at the start and falls every period. That is why early extra payments save far more than the same dollars paid later in the term.

Applications

▸Checking whether a quoted payment matches the amount, rate and term you were offered
▸Deciding between a lower payment on a long term and a higher payment that finishes sooner
▸Planning a payoff strategy when you have spare cash each month
▸Confirming a servicer statement before signing a final amortisation or a payoff quote

Benefits

  • •Locks the numbers to one consistent model instead of relying on a lender summary
  • •Shows the full finance charge, not just the monthly payment
  • •Makes payoff dates and interest savings concrete and comparable
  • •Produces a period-by-period schedule you can hold a servicer to

Limitations

  • •Assumes the rate stays fixed and every payment is made on time
  • •Does not include late fees, insurance, taxes or servicing charges unless you enter them
  • •Rounding conventions differ between lenders, so expect a few dollars of difference from a formal payoff quote
  • •Simple-interest and precomputed (Rule of 78) loans behave differently in the early periods

Best Practices

  • •Compare the finance charge, not the payment, when offers have different terms
  • •Round the payment up rather than down — a small increase trims the term materially
  • •Confirm in writing that extra money goes to principal rather than to the next instalment
  • •Recheck the figures whenever the rate, term or fee changes, since all three interact

Common Misconceptions

Myth: Paying a little extra barely helps
Truth: Even a modest, consistent extra payment removes the highest-interest periods first and can save months of term.
Myth: The payment is what the loan costs
Truth: The finance charge is the cost — a longer term lowers the payment and raises the cost.

Practical Tips

  • •Use the annual view for terms over five years and the monthly view to audit a specific payment.
  • •Keep the schedule on file — it is the fastest way to catch a servicing error.

Common Mistakes

Trusting the opening balance on a statement instead of a payoff quote
Interest accrues daily between the statement date and the payoff date.
Assuming the interest share stays constant
It falls every period, which is the entire point of amortisation.

Assumptions

This calculator makes the following assumptions to provide estimates:

No extra payments in the base schedule: Extra payments are modelled as a separate scenario so both can be compared.

Limitations

Be aware of these limitations when using this calculator:

Limitation: Assumes the rate stays fixed and every payment is made on time
Limitation: Does not include late fees, insurance, taxes or servicing charges unless you enter them
Limitation: Rounding conventions differ between lenders, so expect a few dollars of difference from a formal payoff quote
Limitation: Simple-interest and precomputed (Rule of 78) loans behave differently in the early periods

Frequently Asked Questions

Answers to common questions about this calculator.

How do I read the crossover point?
It is the period where the principal portion of the payment first exceeds the interest portion. After that, every payment accelerates the payoff.
Why does my last payment differ?
Because the balance rarely divides exactly into whole payments, the final payment clears the remaining cents. The calculator reports that final figure separately.
Who uses the personal loan amortization calculator?
It is used by borrowers comparing personal loan offers, by advisers checking a quote before a client signs, and by lenders and brokers sanity-checking a payment, ratio or fee structure. It sits in the Personal Loans group of the Loans & Lending section of Atlascalcs.
How accurate is the personal loan amortization calculator?
Every figure follows directly from the inputs using standard amortisation mathematics, so it is accurate to the quality of the values you enter. Lenders round payments and apply their own day-count conventions, so expect small differences against a formal statement or payoff quote.
How current are the rates and thresholds used here?
The calculator uses the figures you enter, so update the rate to your actual offer or current market quote. Ratio thresholds, poverty guidelines and programme rules reflect the conventions described in the references and change periodically.
Does rounding change the results?
Every calculation runs on full precision and rounds only for display. Lenders round payments to the nearest cent or dollar, so expect a small difference between these figures and a formal statement or payoff quote.
Should I use the payment or the total cost to compare offers?
Use the payment to judge cash flow and the finance charge or APR to judge cost. When two offers differ on both, the all-in cost over the period you expect to hold the loan is the decisive measure.
Can I use this calculator for a business or commercial loan?
Yes. The payment, amortisation, ratio and cost calculators apply the same amortisation mathematics to commercial loans; the difference is in the fees, covenants and collateral rules, which you should enter explicitly.
What information should I have ready before applying?
Your exact rate and term, the fee schedule, any required add-ons, and your gross income and existing monthly obligations. With those five numbers every figure on this page can be tied back to a lender quote.

Related Calculators

Explore more calculators related to this topic.

Related Guides

Deepen your understanding with these educational resources.

Glossary

Technical terms used in mortgage calculations explained in plain language.

Amortisation
Repaying a debt through a schedule of payments that gradually shifts the split from interest to principal until the balance reaches zero.
Amortisation schedule
A period-by-period table showing payment, interest, principal and remaining balance.
Principal
The amount borrowed, excluding interest and fees. Payments applied to principal reduce the balance and therefore future interest.
Rule of 78
A precomputed method that front-loads interest; it makes early payoff less beneficial than simple-interest accounting.
Prepayment
Paying more than the scheduled amount, or repaying the loan early, usually to reduce interest.

Authoritative References

Trusted sources and standards referenced by this calculator.

Applicable Standards

Level-payment (simple-interest) amortisation, payments assumed in arrearsAPR computed by discounting the actual payment stream to net proceedsDebt ratios computed on gross income for lender comparisonsMoney rounded for display only; all calculations run at full precision

Was This Calculator Helpful?

Page Information

Last Updated:

2026-09-21

Version:

2.0.0

License:

Free to use for educational and professional purposes.