20-Year Mortgage Calculator

What is a 20-year mortgage?

A 20-year fixed-rate mortgage is a home loan repaid in 240 equal monthly payments at a rate that never changes. It sits between the 30-year, the default American mortgage, and the 15-year, the aggressive payoff schedule. Lenders price it accordingly: the 20-year usually runs 0.25% to 0.50% below a 30-year and roughly 0.125% to 0.25% above a 15-year, because the lender's money stays outstanding for a middle-length period.

The trade is visible in real numbers. On a $400,000 loan at 6.5%, the 20-year payment is $2,982.29, against $2,528.27 on a 30-year and $3,484.43 on a 15-year. Lifetime interest is $315,750 on the 20-year — $194,428 less than the 30-year's $510,178 and $88,553 more than the 15-year's $227,197. You pay $454.02 a month more than the 30-year and $502.14 a month less than the 15-year. That middle position is the entire product: roughly $450 a month buys five years of your life back and removes close to $200,000 of interest.

The loan fully amortizes, exactly like any other fixed-rate mortgage. Payment 1 on the $400,000 example splits into $2,166.67 of interest and $815.62 of principal, because interest accrues on the balance owed. The split shifts gradually rather than at once: principal first exceeds interest at payment 113, in the tenth year. The 30-year equivalent does not cross over until payment 233, and the 15-year crosses at payment 53. After 12 payments the 20-year balance is $389,916; after 120 payments it is $262,646; payment 240 carries just $16 of interest. Nothing resets, nothing adjusts, and there is no balloon at the end.

Buyers choose the 20-year for one reason: it retires debt quickly without the payment shock of a 15-year. It fits households that can carry a payment about $450 above their 30-year budget line, and it is a common refinance target for owners partway through a 30-year who do not want to service debt for another three decades. Because lenders qualify you against the payment rather than the total interest, the higher figure is what your debt-to-income ratio has to absorb.

How to use this calculator

1. Enter the loan amount — your purchase price minus the down payment.
2. Enter the interest rate for a 20-year fixed; today's quotes are listed on our mortgage rates page. The worked examples here use the 6.5% benchmark rate used across this site.
3. Confirm the term is 20 years — 240 monthly payments.
4. Optionally add property taxes, homeowners insurance, HOA dues, and mortgage insurance for a full PITI figure.
5. Click Calculate to see the monthly payment, total interest, total repaid, and the payment-by-payment amortization schedule.

A realistic input set for a $500,000 purchase with 20% down: loan amount $400,000, rate 6.5%, term 240 months. The calculator returns $2,982.29 of principal and interest. For the optional lines, budget property tax between 0.9% and 1.2% of value a year — $375 to $500 a month on $500,000 — and homeowners insurance at $1,200 to $2,000 a year, which is $100 to $167 a month. Add HOA dues only when the property has them. If your down payment is under 20%, estimate the mortgage insurance line with our PMI calculator: premiums commonly run 0.5% to 1.5% of the loan amount a year, or $198 to $594 a month on a $475,000 balance. Those escrow lines are what push a $2,982.29 loan payment past $3,500 a month in practice.

How it is calculated

Your lender divides the annual interest rate by 12 to get a monthly rate, then solves one question: what level payment, made 240 times, exactly exhausts the balance? The answer is the standard amortization formula. A 20-year differs from a 30-year in exactly one variable — n is 240, not 360.

M = P × [ i (1 + i)ⁿ ] ÷ [ (1 + i)ⁿ − 1 ]

Here M is the monthly principal and interest payment, P is the loan amount, i is the monthly interest rate (annual rate ÷ 12), and n is the number of payments — 240 on a 20-year loan. The formula weights each payment by the compounding factor of the loan, which is why early payments are interest-heavy and late payments are principal-heavy without any change in the amount you send.

Worked example: $400,000 at 6.5% for 20 years

Step 1: the monthly rate is 6.5% ÷ 12 = 0.005416667. Step 2: n = 20 × 12 = 240 payments. Step 3: the compounding factor is (1 + 0.005416667)²⁴⁰ = 3.656447. Step 4: multiply and divide — 400,000 × 0.005416667 × 3.656447 = 7,922.30, and 3.656447 − 1 = 2.656447, so M = 7,922.30 ÷ 2.656447 = $2,982.29. Step 5: total repayment is $2,982.29 × 240 = $715,750, which makes lifetime interest $715,750 − $400,000 = $315,750.

Step 6 compares the first year with the last. During year 1 you send $35,787 to the lender — $25,703 of it is interest and only $10,084 reduces the balance, leaving $389,916 owed after month 12. During the final year just $1,229 of your payments is interest, so $34,559 goes to principal and the balance reaches zero. The interest is front-loaded: $220,521 of the $315,750 is paid in the first 10 years and $95,229 across the last 10. Your first payment carries $2,166.67 of interest; your 240th carries $16.

Worked scenarios

Three inputs move your payment — the rate, the amount borrowed, and the term. Each table below holds two of them constant so you can see the effect of one change at a time. All figures are principal and interest only; taxes, insurance, and mortgage insurance are separate lines.

Rate scenarios: $400,000 loan, 20-year term

Half a percent of rate is worth about $117 a month on this loan — $116.57 moving from 6.00% to 6.50%, $118.91 moving from 6.50% to 7.00% — and roughly $28,000 of lifetime interest. Take every quote on the same day: rate sheets change between visits, and comparing Tuesday's quote with last month's flyer hides the difference.

Term comparison: $400,000 at 6.50%

The 20-year is the middle path: $454.02 more a month ends the loan five years sooner and removes $194,428 of interest. Compared with the 15-year it costs $502.14 less each month and accepts $88,553 more interest. The savings column is arithmetic, not a promotion — a shorter term keeps the balance outstanding for fewer months, so every dollar of interest accrues for less time. Run your own figures in the 15-year and 30-year calculators before you decide, and read the mechanics in the amortization guide.

Down payment scenarios: $500,000 home, 6.50%, 20-year term

Coming to the table with 20% down instead of 5% cuts the payment by $559.18 a month and lifetime interest by $59,203 — and it removes PMI, which on the $475,000 loan would add roughly $198 to $594 a month. Cash versus payment is a personal trade: the down payment calculator runs it at your price point.

Extra payment scenarios: $400,000 at 6.50%, scheduled payment unchanged

Extra principal compresses a loan that is already short. $200 a month retires the balance 2 years 4 months early and saves $42,950. $500 a month turns the 20-year into a 15-year-1-month payoff whose total interest sits within $270 of an actual 15-year loan — the difference is that you kept the lower scheduled payment until you chose to accelerate.

Key details of a 20-year mortgage

• Term and structure. 240 scheduled payments, fully amortizing, no adjustment date, no balloon, and the rate you close at is the rate you keep until payment 240.
• Typical pricing. Commonly 0.25% to 0.50% below a 30-year and 0.125% to 0.25% above a 15-year. The exact spread comes from each lender's price sheet, so request all three terms in one quote request instead of assuming the gap.
• Qualifying payment. $2,982.29 of principal and interest on $400,000 at 6.5%. At the common 28% front-end guideline that alone requires $10,651 of gross monthly income, or $127,813 a year. Add $500 of taxes and insurance and the required income rises to $12,437 a month — $149,241 a year.
• Mortgage insurance. Required below 20% down on conventional loans; premiums commonly run 0.5% to 1.5% of the loan amount a year, which is about $167 to $500 a month on $400,000. You can request removal at 80% of the original value, and your servicer must cancel it automatically at 78%.
• Availability. Most lenders offer a 20-year fixed as a standard conventional term rather than a niche product. If yours does not, another will — and some price it closer to the 15-year than to the 30-year, which is worth checking.
• Prepayment. Conventional loans carry no prepayment penalty, so extra principal, biweekly scheduling, and recasting remain available at any time.
• Refinance use. A frequent target for owners 8 to 10 years into a 30-year; the arithmetic is worked out in the 2026 tips below.

Tips for 2026

• Quote all three terms in one request. Ask each lender for 15-, 20-, and 30-year pricing on the same loan amount, same points, same lock window, on the same day. The spread tells you whether the 20-year is being priced as a bargain or as a premium in that market.
• Settle points versus no points with arithmetic. One point costs 1% of the loan — $4,000 on $400,000 — and typically buys about 0.25% of rate. On the 20-year that takes the payment from $2,982.29 to $2,923.71, a saving of $58.58 a month and $14,059 over the term, with break-even at 68 months. Keep the cash if you may sell or refinance sooner.
• Automate extra principal. $200 a month saves $42,950 and ends the loan 2 years 4 months early. Make it a standing instruction on the payment rather than an annual decision, and see the extra payment calculator for lump sums.
• Qualify on the full payment, not the loan payment. Hold housing under 28% of gross monthly income and total debt under 36% as your own limits, even though many lenders will approve 43%. On $13,000 of gross monthly income that is $3,640 for housing — $2,982.29 plus $500 of taxes and insurance fits at $3,482.29. On $10,000, with $2,800 allowed, it does not.
• Price the refinance before you need it. Eight years into a $400,000 30-year at 6.5%, the balance is $354,627 and 264 payments remain carrying $312,834 of future interest. A 20-year refinance at 6.0% costs $2,540.66 — $12.39 more per month than the current payment — and $255,131 of interest, a saving of $57,703 before closing costs of 2% to 5% ($7,093 to $17,731). Model it in the refinance calculator.
• Build a payment reserve before you accelerate. Six months of payment is $17,894 on this loan, or $20,894 once $500 of taxes and insurance is included. Extra principal earns a guaranteed 6.5% return, but it cannot pay the mortgage in a bad month — fund the reserve first.
• Buy the payment, not a future refinance. Closing costs run 2% to 5% of the loan amount, or $8,000 to $20,000 on $400,000, so the payment you sign in 2026 has to be one you can carry for years without rates falling. Treat any later refinance as a bonus.

Common mistakes on a 20-year mortgage

• Comparing quotes that are not like-for-like. Different points, different lock periods, and quotes taken weeks apart produce a false winner. One point is $4,000 on a $400,000 loan and moves the rate about 0.25%; a stale quote can be half a point off the market. Request the same loan amount, points, and lock window from every lender on the same day.
• Budgeting principal and interest while spending principal, taxes, and insurance. The calculator shows $2,982.29, yet taxes and insurance commonly add $500 to $700 a month. Qualify on the smaller number and your real budget breaks in month one. Check your county's rate with the property tax calculator.
• Choosing the term on lifetime interest alone. "$315,750 of interest" is accurate, and it is not a reason to accept a $454-higher payment you cannot hold through a job change. Total cost and monthly risk are separate questions — the debt-to-income calculator sizes the second one.
• Making extra payments while carrying more expensive debt. An extra $200 a month saves $42,950 here, but if your credit card charges 22% — most do — the card is the better place for that dollar. Clear the expensive debt first, then redirect the cash to principal.
• Ignoring escrow growth. Property taxes and insurance premiums rise, so a payment that fits at closing can be $100 a month higher in three years. Ask for the current escrow analysis and stress-test your budget at the higher figure.
• Opening new credit right after closing. A $400-a-month car payment is about 3 percentage points of debt-to-income on $13,000 of gross monthly income, and it can cost you refinance eligibility later. Postpone large financed purchases until after the loan closes and the reserve is funded.

Frequently asked questions

Is a 20-year mortgage better than a 30-year? It depends on your budget, not on the interest total. At 6.5% on $400,000 the 20-year costs $454.02 more a month and saves $194,428 of interest over five fewer years. If the payment with taxes and insurance stays under 28% of your gross monthly income, the arithmetic favors the 20-year; if it does not, the 30-year is the safer loan.

How much interest do I save with a 20-year? On $400,000 at 6.5%, total interest is $315,750 versus $510,178 on a 30-year — a saving of $194,428 that drops total repayment from $910,178 to $715,750. The saving comes from keeping the balance outstanding for 120 fewer months, so interest accrues for a shorter time on the same rate.

Do all lenders offer 20-year mortgages? Most do; it is a standard conventional term rather than a niche product. If your lender does not, another will. Ask for 15-, 20-, and 30-year pricing in the same request so you can see the actual spread instead of assuming it favors the middle term.

What credit score do I need for a 20-year mortgage? Underwriting matches any conventional loan: 620 is the common floor, 680 clears most lender overlays, and 740+ earns the best pricing. The term adds no requirement of its own — what changes is the payment your debt-to-income ratio must absorb.

Can I refinance from a 30-year into a 20-year? Yes. Eight years into a $400,000 30-year at 6.5% the balance is $354,627; a 20-year refinance at 6.0% payment is $2,540.66 and remaining interest falls from $312,834 to $255,131. Closing costs of 2% to 5% come out of that $57,703 saving, so confirm the break-even before signing.

How much faster does equity build on a 20-year? On the $400,000 example the balance falls to $389,916 after year 1 and $262,646 after year 10, so $137,354 of principal is repaid in the first decade. The 30-year repays $60,895 over the same ten years — less than half — even though both loans amortize on identical math.

Should I choose a 20-year or a 15-year? The 15-year costs $502.14 more a month on $400,000 at 6.5%, finishes five years sooner, and saves another $88,553 of interest. Take the 15-year only if that payment still holds under 28% of gross income with full escrow included; otherwise the 20-year delivers most of the savings at a payment you can sustain.

Can I make extra payments on a 20-year loan? Yes, and conventional loans carry no prepayment penalty. An extra $100 a month ends the loan at 18 years 9 months and saves $23,168; an extra $500 a month ends it at 15 years 1 month and saves $88,285. Every extra dollar goes straight to principal and stops earning 6.5% for the rest of the term.

Related calculators

• 15-Year Mortgage Calculator
• 30-Year Mortgage Calculator
• Full Mortgage Calculator
• Refinance Calculator
• Today's Mortgage Rates
• Amortization Guide