Personal Loan Calculator

Estimate monthly payments, total cost, and interest saved from extra payments. Model origination fees, APR, term, and optional extra contributions to see a full payoff timeline.

Author: Ugo Candido Reviewed by: Finance Content Editor Last updated: Category: Finance → Personal Loans
$
%
%
Fee treatment
$

Used to estimate the payoff month.

Results

Monthly payment $0.00 No extra payments applied
Total interest $0.00 Interest saved with extra: $0.00
Total paid (incl. financed fee) $0.00 Net amount disbursed: $0.00
Months to payoff 0 Reduction vs scheduled: 0 months
Estimated payoff date — Start: —
APR & rate — Monthly rate r: —

Amortization schedule

Amortization schedule with optional extra payments
# Payment Interest Principal Extra Balance
Enter loan details to generate the schedule.

Data Source and Methodology

The calculator follows the Truth in Lending (Regulation Z) Appendix J methodology for closed-end credit. Monthly payments use level-payment amortization where the periodic rate is APR divided by 12. When you add extra payments, the tool simulates the loan month by month, applying each extra amount to principal to compute savings and the new payoff date.

Formulas Used

Periodic rate: \( r = \dfrac{\text{APR}}{12} \)

Payment amount: \( M = \dfrac{P \cdot r}{1 - (1 + r)^{-n}} \) (if \(r > 0\); otherwise \(M = P / n\))

Interest per period: \( \text{Interest}_t = B_{t-1} \cdot r \)

Principal with extra \(E\):\) \( \text{Principal}_t = \min\!\big(M + E - \text{Interest}_t,\; B_{t-1}\big) \)

Balance update: \( B_t = \max\!\big(B_{t-1} - \text{Principal}_t,\; 0\big) \)

Worked Example

Borrow $10,000 at 11% APR for 36 months with a 5% origination fee paid upfront and $50 extra per month:

  1. Scheduled payment (no extra) ≈ $327.37.
  2. Financed principal remains $10,000, but cash disbursed is $9,500 after the fee.
  3. With $50 extra per month, payoff occurs roughly 2 months sooner.
  4. Total interest drops from ≈ $1,861 to ≈ $1,726, saving ≈ $135.
Audit: Complete
Formula (LaTeX) + variables + units
This section shows the formulas used by the calculator engine, plus variable definitions and units.
Formula (extracted LaTeX)
\[','\\]
','\
Formula (extracted text)
Periodic rate: \( r = \dfrac{\text{APR}}{12} \) Payment amount: \( M = \dfrac{P \cdot r}{1 - (1 + r)^{-n}} \) (if \(r > 0\); otherwise \(M = P / n\)) Interest per period: \( \text{Interest}_t = B_{t-1} \cdot r \) Principal with extra \(E\):\) \( \text{Principal}_t = \min\!\big(M + E - \text{Interest}_t,\; B_{t-1}\big) \) Balance update: \( B_t = \max\!\big(B_{t-1} - \text{Principal}_t,\; 0\big) \)
Variables and units
  • P = principal (loan amount) (currency)
  • r = periodic interest rate (annual rate ÷ payments per year) (1)
  • n = total number of payments (years × payments per year) (count)
  • M = periodic payment for principal + interest (currency)
Sources (authoritative):
Changelog
Version: 0.1.0-draft
Last code update: 2026-01-19
0.1.0-draft · 2026-01-19
  • Initial audit spec draft generated from HTML extraction (review required).
  • Verify formulas match the calculator engine and convert any text-only formulas to LaTeX.
  • Confirm sources are authoritative and relevant to the calculator methodology.
Verified by Ugo Candido on 2026-01-19
Profile · LinkedIn

Need more help?

Explore the full suite of personal loan calculators or visit the Loans & Debt hub for broader debt payoff strategies.

, ', svg: { fontCache: 'global' } };

Personal Loan Calculator

Estimate monthly payments, total cost, and interest saved from extra payments. Model origination fees, APR, term, and optional extra contributions to see a full payoff timeline.

Author: Ugo Candido Reviewed by: Finance Content Editor Last updated: Category: Finance → Personal Loans
$
%
%
Fee treatment
$

Used to estimate the payoff month.

Results

Monthly payment $0.00 No extra payments applied
Total interest $0.00 Interest saved with extra: $0.00
Total paid (incl. financed fee) $0.00 Net amount disbursed: $0.00
Months to payoff 0 Reduction vs scheduled: 0 months
Estimated payoff date — Start: —
APR & rate — Monthly rate r: —

Amortization schedule

Amortization schedule with optional extra payments
# Payment Interest Principal Extra Balance
Enter loan details to generate the schedule.

Data Source and Methodology

The calculator follows the Truth in Lending (Regulation Z) Appendix J methodology for closed-end credit. Monthly payments use level-payment amortization where the periodic rate is APR divided by 12. When you add extra payments, the tool simulates the loan month by month, applying each extra amount to principal to compute savings and the new payoff date.

Formulas Used

Periodic rate: \( r = \dfrac{\text{APR}}{12} \)

Payment amount: \( M = \dfrac{P \cdot r}{1 - (1 + r)^{-n}} \) (if \(r > 0\); otherwise \(M = P / n\))

Interest per period: \( \text{Interest}_t = B_{t-1} \cdot r \)

Principal with extra \(E\):\) \( \text{Principal}_t = \min\!\big(M + E - \text{Interest}_t,\; B_{t-1}\big) \)

Balance update: \( B_t = \max\!\big(B_{t-1} - \text{Principal}_t,\; 0\big) \)

Worked Example

Borrow $10,000 at 11% APR for 36 months with a 5% origination fee paid upfront and $50 extra per month:

  1. Scheduled payment (no extra) ≈ $327.37.
  2. Financed principal remains $10,000, but cash disbursed is $9,500 after the fee.
  3. With $50 extra per month, payoff occurs roughly 2 months sooner.
  4. Total interest drops from ≈ $1,861 to ≈ $1,726, saving ≈ $135.
Audit: Complete
Formula (LaTeX) + variables + units
This section shows the formulas used by the calculator engine, plus variable definitions and units.
Formula (extracted LaTeX)
\[','\\]
','\
Formula (extracted text)
Periodic rate: \( r = \dfrac{\text{APR}}{12} \) Payment amount: \( M = \dfrac{P \cdot r}{1 - (1 + r)^{-n}} \) (if \(r > 0\); otherwise \(M = P / n\)) Interest per period: \( \text{Interest}_t = B_{t-1} \cdot r \) Principal with extra \(E\):\) \( \text{Principal}_t = \min\!\big(M + E - \text{Interest}_t,\; B_{t-1}\big) \) Balance update: \( B_t = \max\!\big(B_{t-1} - \text{Principal}_t,\; 0\big) \)
Variables and units
  • P = principal (loan amount) (currency)
  • r = periodic interest rate (annual rate ÷ payments per year) (1)
  • n = total number of payments (years × payments per year) (count)
  • M = periodic payment for principal + interest (currency)
Sources (authoritative):
Changelog
Version: 0.1.0-draft
Last code update: 2026-01-19
0.1.0-draft · 2026-01-19
  • Initial audit spec draft generated from HTML extraction (review required).
  • Verify formulas match the calculator engine and convert any text-only formulas to LaTeX.
  • Confirm sources are authoritative and relevant to the calculator methodology.
Verified by Ugo Candido on 2026-01-19
Profile · LinkedIn

Need more help?

Explore the full suite of personal loan calculators or visit the Loans & Debt hub for broader debt payoff strategies.

]], displayMath: [['\\[','\\]']] }, svg: { fontCache: 'global' } };, svg: { fontCache: 'global' } };

Personal Loan Calculator

Estimate monthly payments, total cost, and interest saved from extra payments. Model origination fees, APR, term, and optional extra contributions to see a full payoff timeline.

Author: Ugo Candido Reviewed by: Finance Content Editor Last updated: Category: Finance → Personal Loans
$
%
%
Fee treatment
$

Used to estimate the payoff month.

Results

Monthly payment $0.00 No extra payments applied
Total interest $0.00 Interest saved with extra: $0.00
Total paid (incl. financed fee) $0.00 Net amount disbursed: $0.00
Months to payoff 0 Reduction vs scheduled: 0 months
Estimated payoff date — Start: —
APR & rate — Monthly rate r: —

Amortization schedule

Amortization schedule with optional extra payments
# Payment Interest Principal Extra Balance
Enter loan details to generate the schedule.

Data Source and Methodology

The calculator follows the Truth in Lending (Regulation Z) Appendix J methodology for closed-end credit. Monthly payments use level-payment amortization where the periodic rate is APR divided by 12. When you add extra payments, the tool simulates the loan month by month, applying each extra amount to principal to compute savings and the new payoff date.

Formulas Used

Periodic rate: \( r = \dfrac{\text{APR}}{12} \)

Payment amount: \( M = \dfrac{P \cdot r}{1 - (1 + r)^{-n}} \) (if \(r > 0\); otherwise \(M = P / n\))

Interest per period: \( \text{Interest}_t = B_{t-1} \cdot r \)

Principal with extra \(E\):\) \( \text{Principal}_t = \min\!\big(M + E - \text{Interest}_t,\; B_{t-1}\big) \)

Balance update: \( B_t = \max\!\big(B_{t-1} - \text{Principal}_t,\; 0\big) \)

Worked Example

Borrow $10,000 at 11% APR for 36 months with a 5% origination fee paid upfront and $50 extra per month:

  1. Scheduled payment (no extra) ≈ $327.37.
  2. Financed principal remains $10,000, but cash disbursed is $9,500 after the fee.
  3. With $50 extra per month, payoff occurs roughly 2 months sooner.
  4. Total interest drops from ≈ $1,861 to ≈ $1,726, saving ≈ $135.
Audit: Complete
Formula (LaTeX) + variables + units
This section shows the formulas used by the calculator engine, plus variable definitions and units.
Formula (extracted LaTeX)
\[','\\]
','\
Formula (extracted text)
Periodic rate: \( r = \dfrac{\text{APR}}{12} \) Payment amount: \( M = \dfrac{P \cdot r}{1 - (1 + r)^{-n}} \) (if \(r > 0\); otherwise \(M = P / n\)) Interest per period: \( \text{Interest}_t = B_{t-1} \cdot r \) Principal with extra \(E\):\) \( \text{Principal}_t = \min\!\big(M + E - \text{Interest}_t,\; B_{t-1}\big) \) Balance update: \( B_t = \max\!\big(B_{t-1} - \text{Principal}_t,\; 0\big) \)
Variables and units
  • P = principal (loan amount) (currency)
  • r = periodic interest rate (annual rate ÷ payments per year) (1)
  • n = total number of payments (years × payments per year) (count)
  • M = periodic payment for principal + interest (currency)
Sources (authoritative):
Changelog
Version: 0.1.0-draft
Last code update: 2026-01-19
0.1.0-draft · 2026-01-19
  • Initial audit spec draft generated from HTML extraction (review required).
  • Verify formulas match the calculator engine and convert any text-only formulas to LaTeX.
  • Confirm sources are authoritative and relevant to the calculator methodology.
Verified by Ugo Candido on 2026-01-19
Profile · LinkedIn

Need more help?

Explore the full suite of personal loan calculators or visit the Loans & Debt hub for broader debt payoff strategies.