# 300k mortgage: what is the payment?

Works out the monthly payment and total interest on a $300,000 mortgage at your rate over 30 years or any term, with the payments over 15, 20 and 30 years side by side.

- Page: https://www.acalculator.org/finance/300k-mortgage-calculator
- JSON spec: https://www.acalculator.org/finance/300k-mortgage-calculator.json
- Version: b86bad2c1204

## Default answer

Example with the default inputs (Loan amount $300,000.00, Interest rate 6.5%, Loan term (years) 30): A 30-year loan of $300,000.00 at 6.5% costs $1,896.20 a month, with $382,633.47 of interest in total.

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| loan | Loan amount | The amount you borrow: $300,000 on this page, or any amount. |
| rate | Interest rate | The fixed yearly rate your lender quotes. The monthly rate is this ÷ 12. |
| years | Loan term (years) | The length of the mortgage, 30 years by default. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| payment | Monthly payment | Principal and interest each month. |
| principal | Loan amount | The amount borrowed. |
| interest | Total interest | Every payment added up, minus the loan. |
| total | Total of payments | The loan plus the total interest. |
| pay15 | Payment over 15 years | The same loan and rate over 15 years. |
| pay20 | Payment over 20 years | The same loan and rate over 20 years. |
| pay30 | Payment over 30 years | The same loan and rate over 30 years. |

## Method

Monthly rate r = yearly rate ÷ 1,200 and n = years × 12 payments. Payment M = L × r ÷ (1 − (1 + r)^−n), or L ÷ n at 0%. Total interest = M × n − L.

## Assumptions

- A fixed rate for the whole term, monthly payments, and no extra payments or fees.
- The payment is principal and interest only: property tax, insurance, HOA dues and mortgage insurance are extra.

## Worked examples

1. loan = $300,000.00, rate = 6.5%, years = 30 gives payment = $1,896.20, interest = $382,633.47, pay15 = $2,613.32, pay20 = $2,236.72. Source: Example 6.111: $99,596 at 5.35% for 30 years, $556.16 a month (rounded up). https://openstax.org/books/contemporary-mathematics/pages/6-12-renting-and-homeownership (retrieved 2026-10-18).
2. loan = $300,000.00, rate = 7%, years = 30 gives payment = $1,995.91, interest = $418,526.69. Source: Example 6.111: $99,596 at 5.35% for 30 years, $556.16 a month (rounded up). https://openstax.org/books/contemporary-mathematics/pages/6-12-renting-and-homeownership (retrieved 2026-10-18).
3. loan = $99,596.00, rate = 5.35%, years = 30 gives payment = $556.16. Source: Example 6.111: $99,596 at 5.35% for 30 years, $556.16 a month (rounded up). https://openstax.org/books/contemporary-mathematics/pages/6-12-renting-and-homeownership (retrieved 2026-10-18).
4. loan = $300,000.00, rate = 0%, years = 30 gives payment = $833.33, interest = $0.00.

## FAQ

### What is the monthly payment on a $300,000 mortgage?

At 6.5% over 30 years, $1,896.20 a month in principal and interest. At 7% it is $1,995.91. Taxes and insurance come on top.

### How much interest will I pay on a $300,000 mortgage?

At 6.5% over 30 years, $382,633.47: you pay $682,633.47 in all for the $300,000. Over 15 years at the same rate, the interest is $170,397.98.

### What is the payment on $300,000 over 15 years?

At 6.5%, $2,613.32 a month: $717.12 more than over 30 years, but $212,235.49 less interest.

### How much income do I need for a $300,000 mortgage?

It depends on your lender, your other debts and your taxes and insurance. The payment here is the principal and interest part; a lender adds the rest and compares the total with your income.

### How is the payment calculated?

With loan L, monthly rate r = yearly rate ÷ 12 and n payments, the payment is L × r ÷ (1 − (1 + r)^−n). At 0%, it is L ÷ n: $300,000 ÷ 360 = $833.33.

## Sources

- OpenStax, Contemporary Mathematics, section 6.12 Renting and Homeownership: the monthly mortgage payment pmt = P × (r/12) × (1 + r/12)^(12t) ÷ ((1 + r/12)^(12t) − 1) for principal P, yearly rate r and t years; total paid = pmt × 12 × t; Example 6.111, $99,596 at 5.35% for 30 years, $556.16 a month. Retrieved 2026-10-18. https://openstax.org/books/contemporary-mathematics/pages/6-12-renting-and-homeownership