Advanced Mortgage Analytics
Master your real estate portfolio. Calculate payments, analyze interest sensitivity, and visualize your 2026 equity trajectory.
Mortgage Payment Formula
This standard formula calculates the fixed monthly payment (M) required to fully amortize a loan of principal (P) over (n) months at a monthly interest rate (r).
M = P [ r(1 + r)^n ] / [ (1 + r)^n – 1 ]
MTotal Monthly Payment
PPrincipal Loan Amount
rMonthly Interest Rate (Annual Rate / 12)
nNumber of Payments (Years × 12)
Example Scenarios
Manual Calculation Example
Calculate the monthly payment for a **$100,000** loan at **6%** annual interest for **30 years**.
1
Convert Rate
Monthly interest rate (r).
6% / 12 = 0.5% = 0.005
2
Calculate n
Total number of payments (n).
30 × 12 = 360
3
Apply Formula
Plug values into the formula.
100,000 × [0.005(1.005)^360] / [(1.005)^360 - 1]
4
Result
Monthly payment.
$599.55
Frequently Asked Questions
How much house can I afford?
A common rule of thumb is the 28/36 rule: spend no more than 28% of your gross monthly income on housing expenses and no more than 36% on total debt.
Does the loan term affect interest?
Yes significantly. A 15-year loan has higher monthly payments than a 30-year loan, but you will pay drastically less in total interest because the money is borrowed for half the time.
What is principal?
Principal is the amount of money you borrowed. Each monthly mortgage payment consists of paying back a portion of the principal plus the interest accrued that month.