Interest-Only Mortgage Calculator

Calculate payments for interest-only mortgages and compare to standard loans. Currently calculating in US Dollar.

Loan Details

Configure your interest-only mortgage

Home Price

Down Payment(20.0%)

Interest Rate6.5%

Total Loan Term30 years

Interest-Only Period10 years

Followed by 20 years of amortizing payments

Loan Amount

$320,000

Payment Shock Warning

After the interest-only period, your payment will increase by $653 (38% increase).

Interest-Only Payment

$1,733

Years 1-10

Amortizing Payment

$2,386

Years 11-30

Total Interest

$460,600

Over 30 years

Extra Interest Cost

+$52,458

vs standard mortgage

Payment Comparison

Interest-only vs standard mortgage payments

Balance Over Time

Loan balance stays flat during interest-only period

Payment Schedule

Year-by-year breakdown showing both phases

Year	Phase	Payment	Principal	Interest	Balance
1	Interest-Only	$1,733	$0	$20,800	$320,000
2	Interest-Only	$1,733	$0	$20,800	$320,000
3	Interest-Only	$1,733	$0	$20,800	$320,000
4	Interest-Only	$1,733	$0	$20,800	$320,000
5	Interest-Only	$1,733	$0	$20,800	$320,000
6	Interest-Only	$1,733	$0	$20,800	$320,000
7	Interest-Only	$1,733	$0	$20,800	$320,000
8	Interest-Only	$1,733	$0	$20,800	$320,000
9	Interest-Only	$1,733	$0	$20,800	$320,000
10	Interest-Only	$1,733	$0	$20,800	$320,000
11	Amortizing	$2,386	$8,068	$20,562	$311,932
12	Amortizing	$2,386	$8,608	$20,022	$303,325
13	Amortizing	$2,386	$9,184	$19,446	$294,140
14	Amortizing	$2,386	$9,799	$18,831	$284,341
15	Amortizing	$2,386	$10,456	$18,174	$273,885
16	Amortizing	$2,386	$11,156	$17,474	$262,729
17	Amortizing	$2,386	$11,903	$16,727	$250,826
18	Amortizing	$2,386	$12,700	$15,930	$238,126
19	Amortizing	$2,386	$13,551	$15,079	$224,575
20	Amortizing	$2,386	$14,458	$14,172	$210,117
21	Amortizing	$2,386	$15,427	$13,203	$194,690
22	Amortizing	$2,386	$16,460	$12,170	$178,230
23	Amortizing	$2,386	$17,562	$11,068	$160,668
24	Amortizing	$2,386	$18,738	$9,892	$141,930
25	Amortizing	$2,386	$19,993	$8,637	$121,937
26	Amortizing	$2,386	$21,332	$7,298	$100,605
27	Amortizing	$2,386	$22,761	$5,869	$77,844
28	Amortizing	$2,386	$24,285	$4,345	$53,559
29	Amortizing	$2,386	$25,912	$2,718	$27,647
30	Amortizing	$2,386	$27,647	$983	$0

Interest Cost Comparison

See how interest-only affects total borrowing cost

Standard Mortgage

Fixed $2,023/month for 30 years

$408,142

Total Interest

Interest-Only Mortgage

$1,733/mo then $2,386/mo

$460,600

Total Interest

About Interest-Only Mortgages

Pros

Lower initial monthly payments
More cash flow flexibility early on
Good for irregular income (bonuses, commissions)
Can invest payment difference elsewhere

Cons

No equity building during I/O period
Payment shock when amortization begins
Higher total interest cost
Risk if home value decreases

Interest-only mortgages are best suited for borrowers with irregular income who can handle the payment increase, or those who plan to sell or refinance before the amortizing period begins.