Free Mortgage Calculator – Estimate Your Monthly Payments
Direct Answer: To calculate your monthly mortgage payment, use the standard fixed-rate amortizing loan formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ], where principal P is the property price minus your deposit. Enter your property price, down payment, interest rate, and loan term below to see your monthly payment, total interest, and Loan-to-Value (LTV) ratio.
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🔍 About This Calculator
This free tool provides a quick, transparent estimate for projecting monthly mortgage payments, total interest, and Loan-to-Value (LTV) ratios.
Formula Used
M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
What It Does
Calculates fixed monthly principal and interest payments across conventional, FHA, or VA home loans.
Computes Loan-to-Value (LTV) percentage to evaluate equity levels and private mortgage insurance thresholds.
Calculates cumulative lifetime interest costs and total mortgage repayment value.
Important Limitations
⚠️ This is an estimate only and does not constitute an official mortgage loan offer or pre-approval.
⚠️ This calculator excludes local property taxes, homeowners insurance, HOA fees, and PMI, which increase total monthly housing payments.
⚠️ Always consult a licensed mortgage broker or financial advisor before committing to a home purchase.
Data Privacy
✅ All calculations are performed entirely in your browser. We never store, transmit, or monetize your property or financial details.
📚 Methodology & Data Sources
This calculator estimates your monthly mortgage payments, total interest, and Loan-to-Value ratio using the standard amortization formula. Here is exactly how it works.
Core Mortgage Formula
Your monthly mortgage payment is calculated using the standard fixed-rate amortizing loan formula:
M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
Where:
M = Monthly Payment
P = Principal Loan Amount (Property Price – Deposit)
i = Monthly Interest Rate (Annual Rate ÷ 12)
n = Total Number of Payments (Loan Term in Years × 12)
Loan-to-Value (LTV) Ratio:LTV = (Principal / Property Price) × 100, a key metric that lenders use to assess risk and determine product eligibility.
Key Assumptions
Fixed Interest Rate – The rate is assumed to remain constant for the entire loan term.
Monthly Compounding – Interest is calculated and added to the balance monthly.
Fully Amortizing – Each payment covers both interest and principal, with the balance reaching zero at the end of the term.
No Additional Costs – Escrow charges (property taxes, hazard insurance, HOA dues) and loan origination fees are not included in the basic calculation.
This is an estimate only. The result is an illustrative calculation. It is not a mortgage offer, a guarantee of lending, or a substitute for a full affordability assessment from a lender.
Excludes additional costs. Product fees, valuation fees, legal fees, and property taxes are not included. These can significantly impact the total cost and monthly payment.
Fixed-rate assumption. This does not model interest-only mortgages or variable-rate products.
Lender criteria vary. A manageable payment in this calculator does not guarantee approval, as lenders assess credit profile, income stability, and other debts.
🛡️ Professional Advice Disclaimer: The TrueCalco Mortgage Calculator is a general estimation tool. It does not constitute financial or mortgage advice. We strongly recommend consulting a qualified mortgage advisor or your chosen lender for a personalized assessment. Your home may be repossessed if you do not keep up repayments on your mortgage.
How We Handle Your Data (Privacy)
✅ All calculations run in your browser. No data you enter—including your financial details or personal information—is ever transmitted to our servers or stored. TrueCalco is 100% client-side.
How Does a Mortgage Calculation Look in Real Life? (Worked Example)
📌 Real-World Example: $300,000 Home Purchase
A buyer purchasing a $300,000 home with a $60,000 down payment (20% deposit) at a 6.5% interest rate on a 30-year fixed term:
Computation Step
Formula / Input Parameter
Calculated Output
1. Purchase Price
Home Value Entered
$300,000.00
2. Down Payment (20%)
Cash Deposit Applied
$60,000.00
3. Principal Borrowed (P)
$300,000 – $60,000
$240,000.00
4. Loan-to-Value (LTV)
($240,000 ÷ $300,000) × 100
80.0%
5. Monthly Payment (M)
M = $240k × [0.005417(1.005417)³⁶⁰] ÷ [(1.005417)³⁶⁰ – 1]
$1,516.96 / month
6. Total Interest Paid
($1,516.96 × 360) – $240,000
$306,106.84
7. Total Lifetime Cost
Principal ($240,000) + Total Interest ($306,106.84)
$546,106.84
Frequently Asked Questions: Mortgage Calculations
The formula for a fixed-rate repayment mortgage is: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ], where M is the monthly payment, P is the principal loan amount (property price minus deposit), i is the monthly interest rate (annual rate divided by 12), and n is the total number of payments (term in years × 12).
No. A mortgage calculator provides an illustrative estimate for planning purposes. It is not a mortgage offer or guarantee of lending. A full affordability assessment from a lender is required before obtaining an official mortgage offer.
Loan-to-Value (LTV) is the percentage of the property value you are borrowing relative to the purchase price: LTV = (Loan Principal ÷ Property Price) × 100. Lower LTV ratios (such as 80% or below) generally qualify for lower interest rates and exempt conventional borrowers from private mortgage insurance (PMI).
A 15-year mortgage requires higher monthly payments but saves tens of thousands of dollars in cumulative lifetime interest. A 30-year mortgage offers lower, more manageable monthly payments, giving you greater cash flow flexibility.
📖 Complete In-Depth Guide
Learn More About Mortgage Affordability in Our Complete Guide
Understand debt-to-income ratios, amortization mechanics, down payments, and closing costs to make a confident home buying decision.