Free Mortgage Calculator — Monthly Payment + Amortization Schedule

Monthly payment, total interest, year-by-year amortization. Extra-payment what-if. US fixed-rate mortgage math.

Mortgage Calculator computes the monthly payment (principal + interest), total interest paid over the life of the loan, and a full amortization schedule for any US fixed-rate mortgage. It also shows what an extra monthly payment would do: months saved, interest saved, and the new payoff date.

The math is the standard mortgage formula: M = P × (r(1+r)^n) / ((1+r)^n − 1) where P is the loan amount, r is the monthly interest rate (APR ÷ 12), n is the total number of months. Each row of the amortization table tracks how each payment splits between interest (decreasing) and principal (increasing) over time.

Free, no signup, browser-side. No data is sent to any server — your loan details stay in your tab. Useful for: comparing mortgage offers from different lenders, deciding whether to make extra principal payments, refinance math, or simply seeing how much interest you'll pay over 30 years on a $300k loan at 7%.

Key features

Monthly P&I calculation — Standard mortgage payment formula. Result updates live as you edit any input.
Full amortization schedule — Year-by-year breakdown of payment / interest / principal / remaining balance. Expandable from a single click.
Extra-payment what-if — Add an extra amount to each monthly payment — see how many months and how many dollars in interest you save.
Principal vs interest split — Live percentage bar showing how much of your total payments goes to principal vs interest over the life of the loan.
Browser-side only — Loan amount, rate, term — all stay in your browser tab. Pickrack never sees your numbers.

How to use

Step 1: Enter loan amount + interest rate — E.g., $300,000 at 7.0% APR. Use the current rate quoted by your lender.
Step 2: Enter loan term — Most US mortgages are 30-year or 15-year. Shorter terms = higher monthly payment but much less total interest.
Step 3 (optional): Add extra monthly payment — Try $100/month or $200/month — watch the months saved and interest saved numbers update. Even small extra payments early in the loan have outsized impact.
Step 4: View amortization — Click 'Show table' to see year-by-year breakdown. Useful for tax-prep (interest paid per year is itemizable in the US).

When to use

Compare two mortgage offers — same amount + term but different rates → which has lower monthly payment?
Decide on extra payments — see whether $200/month extra is worth it (often saves $50k+ over a 30-year loan)
Refinance math — new lower rate vs closing costs → break-even month
Buy-vs-rent budgeting — calculate true monthly housing cost (P&I + property tax + insurance separately)
Year-end tax prep — pull annual interest paid for itemized deduction (US homeowners)
Mortgage acceleration planning — how much extra to pay to be debt-free by retirement

Frequently asked questions

Does this include property tax, insurance, HOA, or PMI?

No — this calculates only Principal + Interest (P&I), which is what most lenders quote. Add property tax (~1-2% of home value per year), homeowners insurance (~0.5%), HOA fees (if applicable), and PMI (~0.5-1% if down payment < 20%) for the true monthly housing cost. The PITI total is typically 25-50% higher than P&I.

What's the difference between APR and interest rate?

Interest rate is the cost of the loan itself. APR includes the interest rate PLUS lender fees / points / mortgage insurance — it's a more accurate yearly cost. Use APR when comparing mortgage offers from different lenders. The calculator takes the interest rate (use APR if comparing offers, or rate if you've already chosen a lender).

How does extra payment math work?

Each month the calculator subtracts both the regular monthly payment AND the extra amount from the principal. Since interest is computed on the remaining balance, extra payments shrink the balance faster, which shrinks all future interest. The earlier in the loan you make extra payments, the bigger the impact.

Why is the balance still positive after the term ends?

If your interest rate is very high (>20%) or term very short, the standard payment formula might not fully pay off the loan within the term. This rarely happens with realistic inputs. If it does, increase the term or the payment manually.

Adjustable-rate (ARM) mortgage support?

Not in v1 — this is fixed-rate only. ARM calculations need adjustment caps, periodic caps, and lifetime caps. Use the bank's official ARM calculator or assume a worst-case fixed rate after the initial period.

Is bi-weekly payment supported?

Not directly. Workaround: multiply your monthly payment by 26/12 and use that as an 'extra monthly' equivalent (since bi-weekly = 26 payments/year = 13 monthly equivalents). Native bi-weekly support is on the roadmap.

Are these numbers tax-deductible advice?

No — Pickrack provides math, not financial or tax advice. Mortgage interest deduction rules vary by US state, year, and loan size (TCJA capped at $750k for primary residences post-2017). Consult a tax professional.

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