Mortgage terms in plain English

The amount you actually borrow.

Principal is the raw loan balance — the money the bank hands over to buy the house, before any interest is added. Every payment you make is split into two buckets: some of it pays interest, and whatever's left shrinks the principal.

Example: Borrow $200,000 and your starting principal is $200,000. After a few years of payments it might be $185,000 — that difference is the equity you've built.

In this toolkit: The calculator uses principal as the starting balance for the amortization schedule. Change it and every payment, total interest, and payoff date recalculates.

The lender's monthly fee for letting you borrow.

Interest is the price of the money. Each month the lender charges you a slice of your remaining balance based on your interest rate. Because that slice is calculated on the balance you still owe, the interest bill shrinks a little every month as you pay principal down.

Example: At 6.375%, a $200,000 balance costs about $1,062.50 in interest in the very first month. Next month the balance is a little lower, so the interest is a little lower, too.

How long you have to pay the loan off.

The term is the full length of the loan, usually in years. A longer term means smaller monthly payments but a lot more interest paid over time. A shorter term is the opposite — bigger monthly payments but far less interest.

Example: A 30-year term means 360 monthly payments. A 15-year loan on the same amount is roughly twice the monthly payment but often saves six figures in interest.

In this toolkit: In every calculator, the term controls how many rows appear in the amortization schedule and how the payoff milestones line up on the timeline.

The rate never changes for the life of the loan.

With a fixed-rate loan your interest rate — and therefore your principal-and-interest payment — is locked in from day one until you pay it off. Predictable, no surprises. Most 15- and 30-year loans are fixed.

Example: A 30-year fixed at 6.5% will still be 6.5% in year 29, even if rates in the market are 3% or 12% by then.

The rate starts low, then can move up or down.

An ARM has a low starting rate for a few years (usually 5, 7, or 10), and then adjusts periodically based on a market index. Payments can go up quickly once the fixed period ends. Useful if you plan to sell or refinance before the adjustment kicks in.

Example: A '7/6 ARM' is fixed for 7 years, then adjusts every 6 months for the remaining term.

Replacing an existing loan with a new one.

Refinancing means paying off your current mortgage with a brand-new one — usually to get a lower rate, change the term, or pull cash out of your equity. It has its own closing costs, so it only makes sense when the savings outweigh those costs.

Example: Dropping from 7.5% to 6.0% on a $300k balance saves roughly $300/month — worth it if closing costs pay back within a few years.

In this toolkit: The Break-even (Points) tool works the same way for refinances: compare monthly savings against upfront cost.

The percentage used to calculate your interest each month.

The interest rate — sometimes called the 'note rate' — is the number the lender uses to figure out how much interest to charge on the balance. It does NOT include fees, which is why APR exists.

Example: A 6.375% rate means the lender charges 6.375% per year on whatever balance is still outstanding.

The rate with fees baked in — the fair-comparison number.

APR is a standardized figure that combines the interest rate with most upfront lender fees (origination, discount points, some closing costs). It exists so you can compare loans apples-to-apples: a loan with a low rate but heavy fees may quietly have a higher APR than a loan with a slightly higher rate and no fees.

Example: A 6.375% rate loan with $6,000 in fees might have an APR of around 6.65%. Two loans, same rate — the one with the lower APR is cheaper.

In this toolkit: The Compare Loans tool shows APR next to rate so you can see which loan is truly less expensive after fees.

What the lender charges to set the loan up.

A flat fee (often 0.5%–1% of the loan) that pays for underwriting, processing, and the loan officer's work. It's part of closing costs and shows up in APR.

Example: 1% origination on a $200,000 loan is $2,000, due at closing.

The one-time fees you pay to finalize the loan.

A bundle of upfront charges — origination, title insurance, appraisal, recording fees, prepaid taxes and insurance, and more. Usually 2–5% of the loan amount. You either bring cash for them at closing or roll them into the loan (which increases the balance).

Example: On a $250,000 loan, expect $5,000–$12,500 in closing costs.

The lender guarantees your rate for a set window.

Rates move daily. A rate lock freezes the quoted rate for 30, 45, or 60 days so it doesn't jump between application and closing. Long locks sometimes cost a little more.

Example: You lock at 6.5% for 45 days on Monday. Even if rates spike to 7% on Friday, you still close at 6.5%.

The core mortgage payment, before taxes and insurance.

P&I is just the loan-repayment part of your monthly bill — what pays down principal plus the interest owed that month. On a fixed-rate loan, P&I is the same dollar amount every month for the entire term.

Example: A $1,177 P&I payment stays $1,177 in month 1 and in month 360, even though the split between principal and interest shifts over time.

The true monthly housing cost — Principal, Interest, Taxes, Insurance.

PITI is what most people actually pay each month. It rolls the P&I payment together with property taxes and homeowners insurance (and PMI if applicable). It's the number to use when checking affordability.

Example: $1,177 P&I + $300 taxes + $100 insurance = $1,577 PITI.

In this toolkit: The Full Analysis tool always shows PITI — not just P&I — so you know the real number that hits your bank account.

The month-by-month plan for paying the loan off.

Amortization is the schedule that shows how each payment is split between interest and principal, month by month, until the balance hits zero. Because interest is charged on the remaining balance, early payments are mostly interest and later payments are mostly principal — the schedule tells you exactly how that flips over time.

Example: Month 1 of a $200k / 6.375% / 30-year loan: about $1,062 interest + $87 principal. Month 300: about $155 interest + $994 principal.

In this toolkit: Every 'View schedule' table in this toolkit is an amortization schedule. You can export any of them to CSV.

Money paid on top of your normal payment that goes straight to the balance.

Any dollar you send beyond your scheduled payment goes directly to principal — it skips the interest bucket entirely. That means every extra dollar saves you future interest and shortens the loan.

Example: Adding just $100/month to a 30-year mortgage typically shaves 4–5 years off the payoff and saves tens of thousands in interest.

In this toolkit: The 'Extra monthly principal' field in each tool lets you see the exact payoff date and interest savings from making extra payments.

The month your balance finally hits zero.

The payoff date is when you make your very last payment. It depends on your term AND on any extra payments you make — send more, and it comes sooner.

Example: A 30-year loan started in July 2026 has a scheduled payoff of June 2056 — but $200/month extra might move that to 2050.

The full amount of interest you'll pay over the life of the loan.

Add up every dollar of interest from every payment — that's total interest paid. It's often more than the original loan amount on longer terms, which is why extra payments and shorter terms are so powerful.

Example: $200,000 borrowed at 6.375% for 30 years costs about $249,000 in interest — more than the house.

A period where you only pay interest — no principal.

During an interest-only period, your payment covers only the interest owed. The principal balance doesn't shrink at all. Payments are lower, but you're not building equity from the loan (only from home appreciation).

Example: A 10-year I/O period on a 30-year loan: you pay interest only for years 1–10, then principal payments start in year 11 on the remaining 20-year schedule.

A fee some lenders charge if you pay off the loan early.

A prepayment penalty is a fee for paying the loan off — via extra payments, refinance, or selling the house — before a set date. Most modern loans have no prepayment penalty, but always check the note.

Example: 'No PPP' on a term sheet means you can pay ahead, refinance, or sell without any penalty.

Monthly insurance the lender requires when your down payment is under 20%.

PMI protects the LENDER (not you) if you stop paying. It's added to your monthly payment whenever your loan is more than 80% of the home's value. The good news: once you cross 20% equity, PMI drops off automatically.

Example: PMI usually costs 0.3%–1.0% of the loan per year. On a $250k loan that's roughly $60–$210/month, until you hit 20% equity.

In this toolkit: In the Full Analysis and Compare Loans tools, the payoff timeline marks the exact month PMI is scheduled to drop.

Insurance that protects your house — required by the lender.

Covers fire, theft, storm damage, and liability. The lender requires it because the house is their collateral. Usually paid monthly through escrow along with your mortgage payment.

Example: $100–$150/month is a common range for a modest single-family home.

The annual tax your city or county charges on the home.

Property tax is billed once or twice a year by the local government, but most mortgages collect 1/12 of it monthly through escrow so the lender can pay the bill on time. Rates vary wildly by location.

Example: A $250,000 home at a 1.2% tax rate owes $3,000/year — about $250/month collected in escrow.

A holding account the lender uses to pay taxes and insurance for you.

Instead of writing separate checks to the tax collector and insurance company, you send extra money each month with your mortgage payment. The lender parks it in an escrow account and pays those bills when they come due. Some investment or jumbo loans allow you to waive escrow and pay directly.

Example: 'Escrow waived' on an investment loan means you're responsible for cutting the tax and insurance checks yourself.

Monthly or annual fees paid to a homeowners association.

If your home is in a subdivision, condo building, or planned community, HOA dues fund shared amenities — pools, landscaping, exterior maintenance. Not paid through the lender, but real money that affects affordability.

Example: A townhome HOA might be $150–$400/month; a full-service condo can be $600+.

What the house is worth today.

The market value of the home — usually determined by a licensed appraiser during the loan process. This is the 'V' in LTV, and it's what your equity is measured against.

Example: You buy for $260,000, but the appraisal comes in at $255,000. The lender uses $255,000 for LTV calculations.

How much of the home's value is financed, as a percent.

LTV is your loan amount divided by the home's value. Lower is better — it means more equity, less risk to the lender, better rates, and often no PMI. LTV drops naturally over time as you pay principal AND as the home appreciates.

Example: $185,000 loan on a $250,000 home = 74% LTV. Cross under 80% and PMI drops.

In this toolkit: The '80% LTV / PMI drop' milestone on every timeline is triggered by this exact number.

The cash you put in upfront to buy the house.

Your down payment is home price minus loan amount. A bigger down payment lowers LTV, may eliminate PMI, and gets you a better rate. Common minimums: 3% (conventional), 3.5% (FHA), 0% (VA/USDA if eligible).

Example: $50,000 down on a $250,000 home = 20% down, no PMI, 80% LTV.

The slice of the home you actually own.

Equity = home value − remaining loan balance. It grows as you pay principal, as the home appreciates, or (best) both. It's real wealth — you can borrow against it, or cash it out when you sell.

Example: $300,000 home − $210,000 balance = $90,000 equity (30%).

In this toolkit: The 25% / 50% / 75% equity milestones on the payoff timeline mark when you own that share of the home.

How much the home rises in value over time.

Long-term home price growth. Historically 3–5% per year in the U.S., though wildly local and never guaranteed. Appreciation quietly builds equity even if you make only minimum payments.

Example: A $250,000 home appreciating 3%/year is worth $335,000 in ten years — an $85,000 gain, on top of any principal paid down.

Cash paid upfront to buy a lower interest rate.

One 'point' equals 1% of your loan amount, paid at closing. In exchange the lender lowers your interest rate — usually somewhere around 0.25% per point. Great if you keep the loan long enough for the monthly savings to outrun the upfront cost.

Example: 1.75 points on a $188,700 loan costs $3,302 at closing but might drop your rate 0.5%, saving ~$60/month.

In this toolkit: The Points vs. No-Points tool exists specifically to answer 'is this worth it for how long I'll actually keep the loan?'

When the monthly savings from points finally equal what you paid for them.

If points cost $3,000 upfront but save you $60 a month, you 'break even' at month 50 — from then on, the savings are pure win. Keep the loan past break-even and points pay off. Sell or refinance sooner and you lose money on them.

Example: $3,302 in points ÷ $60/month savings ≈ 55 months (about 4.6 years) to break even.

In this toolkit: The Points tool displays the break-even month prominently — and warns you when it lands after a typical move-out date.

The opposite of points — the lender pays you upfront in exchange for a higher rate.

Instead of paying to lower your rate, you can take a slightly higher rate and have the lender chip in cash toward closing costs. Great when you're short on cash at closing or don't plan to keep the loan long.

Example: Accepting a 6.75% rate instead of 6.5% might come with a $2,500 lender credit toward closing costs.

Replacing your loan with a bigger one and pocketing the difference.

You refinance for more than you currently owe, and receive the extra as cash at closing — usually to consolidate debt, renovate, or invest. The new balance is larger and the new rate resets, so it's a real tradeoff.

Example: Owe $180k on a $300k home. Cash-out refi to $240k → walk away with $60k (minus closing costs), but now you're paying interest on $240k.

The exact dollar amount you bring (or receive) at closing.

Cash to close = down payment + closing costs − lender credits − seller credits. It's the number the title company tells you to wire. On a refinance it can even be negative — meaning you get money back.

Example: $50,000 down + $8,000 closing − $2,000 seller credit = $56,000 wire to title.

The lender's official quote — required within 3 days of applying.

A standardized 3-page document showing your rate, monthly payment, closing costs, and cash to close. Every lender's LE is formatted the same way, so it's the best apples-to-apples comparison tool available.

Example: Get LEs from 2–3 lenders on the same day and stack them side-by-side.

The final numbers — must be delivered 3 days before closing.

The CD is the final version of the loan estimate, with all costs locked in. By law you get it at least 3 business days before signing, so there are no surprises at the closing table.

Example: Compare the CD to your original LE — big changes should be explained.

How much of your income goes to debt payments each month.

DTI = total monthly debt payments ÷ gross monthly income. Lenders use it to decide how much you can afford. Most conventional loans cap DTI around 43–50%.

Example: $2,500 in monthly debts on $7,000 gross income = 36% DTI.

A three-digit number lenders use to price your risk.

Higher scores unlock lower rates. Mortgage lenders typically use FICO scores, and pull all three bureaus. Common tiers: 760+ (best), 740–759, 720–739, 700–719, 680–699, and so on down.

Example: The gap between a 760 and a 680 score can be a full 0.5% in rate — hundreds of dollars a month.