Updated 2026-04

Loan Comparison Calculator

Compare two loan repayment methods: standard amortizing (level payments, more interest) vs equal-principal (declining payments, less interest). See total cost difference.

Loan Comparison Calculator

Compare two loan offers side-by-side. Look at Total of Payments (principal + interest + fees) for the apples-to-apples cost over the life of the loan, not just the headline APR.

Option A

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Option B

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How to use

  1. 1 Enter loan principal (amount borrowed).
  2. 2 Enter the APR % (annual interest rate).
  3. 3 Enter loan term in months (e.g., 360 for 30-year mortgage, 60 for 5-year auto).
  4. 4 Click Calculate to see: amortizing monthly payment + total interest, equal-principal first payment + last payment + total interest, and the savings difference.
  5. 5 Note: most US lenders only offer amortizing. Equal-principal common for: commercial real estate, business loans, some construction loans, international mortgages. Ask lender if available.

FAQ

Q What is the difference between amortizing and equal-principal?

AMORTIZING: same monthly payment for life of loan. Early payments are mostly interest. EQUAL-PRINCIPAL: fixed principal portion + declining interest = declining payments. Equal-principal saves 5-15% on total interest but starts with higher payments.

Q Why do US mortgages use amortizing?

Predictable monthly payment for borrowers; standardized for secondary market (Fannie/Freddie MBS); more interest revenue for lenders. Equal-principal common in commercial real estate, construction, business loans, and many international markets (Korea, Japan, parts of Europe).

Q How much does equal-principal save?

Typically 5-15% of total interest. On a $300,000 30-yr loan @ 6.30%: amortizing total interest = $368,520; equal-principal = $284,625 — saves $83,895 (23%). The savings increase with longer terms and higher rates.

Q Can I get an equal-principal mortgage in the US?

Rarely. Most US lenders only offer amortizing. Some portfolio lenders, credit unions, and commercial RE lenders offer equal-principal. Alternative: take amortizing loan and ADD extra principal each month (DIY equal-principal — most lenders allow without penalty).

Q Is bi-weekly payment same as equal-principal?

NO. Bi-weekly = paying half monthly amount every 2 weeks = 26 half-payments = effectively 13 monthly payments per year. Saves 6+ years on a 30-year mortgage. Different from equal-principal which restructures the principal/interest ratio.

Q When does amortizing make more sense?

When budget stability matters most: (1) tight budget, fixed income, (2) want to invest the difference in higher-return assets, (3) tax deduction maximizes early-year mortgage interest deduction, (4) plan to sell within 5-7 years (interest cost similar early on).

Q When does equal-principal make more sense?

When you can handle higher early payments and want to minimize total cost: (1) high income now expected to decrease, (2) commercial property where rents grow, (3) construction loan, (4) investment account growth doesn't justify the interest cost.

Q How can I simulate equal-principal with my US amortizing mortgage?

Calculate principal portion of each amortizing payment + add the difference between equal-principal and amortizing as extra principal payment. Most lenders accept extra principal monthly without penalty. Effectively same total interest savings as true equal-principal loan.