Piggyback Loan Calculator

Piggyback Loan Calculator

80-10-10 piggyback loans combine two mortgages to avoid PMI while putting less than 20% down.

What This Calculator Shows

• Monthly Payment: Your expected payment amount based on loan terms
• Total Interest: The cost of borrowing over the loan lifetime
• Amortization Schedule: How payments split between principal and interest
• Payment Breakdown: Visual representation of your loan costs

How to Calculate

1. Enter your loan amount 2. Input the interest rate (APR) 3. Select the loan term 4. Review your payment details and total costs

Key Considerations for Piggyback Loan

• Compare offers from multiple lenders before committing
• Understand all fees including origination, closing costs, and prepayment penalties
• Consider how rate changes might affect your payments (for variable rates)
• Factor in your overall financial goals and debt-to-income ratio

An 80-10-10 piggyback splits financing into an 80% first mortgage, a 10% second, and 10% down — avoiding PMI without a 20% deposit.

On a $400,000 home:

Structure	Monthly cost
80% first at 6.5% ($320,000)	$2,023
10% second at 8% ($40,000, 15yr)	$382
Piggyback total	$2,405
90% single loan at 6.5% + PMI	$2,276 + $150 PMI = $2,426

The saving is small and comes with a trade: the second lien is usually variable, and it does not fall away the way PMI does once you reach 20% equity. PMI on a conventional loan terminates automatically at 78% LTV; the second mortgage runs its full term unless you pay it off.

The Numbers This Page Opens With

The calculator above starts at $60,000 over 15 years at 8%, which is representative for this product:

Monthly payment	$573
Total repaid	$103,210
Total interest	$43,210
Interest as a share of principal	72%

Change any input above and every figure recalculates. The amortisation formula behind it:

`` M = P × [ r(1+r)^n ] / [ (1+r)^n − 1 ]

P = principal, r = monthly rate (annual ÷ 12), n = number of payments ``

Before You Sign

• Compare APR, not the rate. APR includes origination and points; the rate does not.
• Ask about prepayment penalties. They turn a plan to pay early into a fee.
• Rate-shop inside 14 days. Credit scoring models treat multiple mortgage or auto

enquiries in that window as one enquiry.

• Check whether the payment includes escrow. A mortgage quote without taxes and insurance

understates the real monthly cost by hundreds.

Where the Money Goes

On $60,000 at 8% over 15 years, paying $573 a month:

Point	Principal repaid	Interest paid	Balance
Year 2	$3,304	$7,017	$56,696
Year 4	$9,064	$16,738	$50,936
Year 8	$21,288	$30,317	$38,712
Year 11	$37,772	$39,636	$22,228
Year 15	$60,000	$43,210	$0

Early payments are mostly interest. That is not a fee structure — it is arithmetic: interest accrues on the outstanding balance, which starts at its largest. It is also why an extra payment made early saves far more than the same payment made late.

What a Rate Change Costs

Rate	Monthly	vs 8%	Total repaid
7.00%	$539	-$34	$97,073
7.50%	$556	-$17	$100,117
8.00%	$573	—	$103,210
8.50%	$591	+$17	$106,352
9.00%	$609	+$35	$109,541

Half a percentage point moves the monthly payment by $17 and the total by $3,141. Shopping three lenders usually beats any amount of negotiating on price.