Sarah Martinez · Golden Key Realty
Run the numbers
15 calculators for the questions that actually come up — what it costs a month, what you need up front, what a sale would leave you with. Nothing is saved and nothing is sent unless you ask for it.
What would the monthly payment be?
Estimated monthly payment · 30-year fixed
$4,630/mo
Loan amount
$600,000
Down payment
$150,000
Interest over the life
$765,267
| Principal & interest | $3,792 |
| Property tax | $688 |
| Homeowners insurance | $150 |
| Total monthly | $4,630 |
In the first year, 85% of what you pay the lender is interest. That share falls every year.
Year by year
| Interest paid | Principal paid | Balance left | |
|---|---|---|---|
| Year 1 | $38,803 | $6,706 | $593,294 |
| Year 2 | $38,353 | $7,155 | $586,138 |
| Year 3 | $37,874 | $7,635 | $578,503 |
| Year 4 | $37,363 | $8,146 | $570,357 |
| Year 5 | $36,817 | $8,692 | $561,666 |
| Year 6 | $36,235 | $9,274 | $552,392 |
| Year 7 | $35,614 | $9,895 | $542,497 |
| Year 8 | $34,951 | $10,557 | $531,940 |
| Year 9 | $34,244 | $11,264 | $520,676 |
| Year 10 | $33,490 | $12,019 | $508,657 |
| Year 11 | $32,685 | $12,824 | $495,833 |
| Year 12 | $31,826 | $13,683 | $482,150 |
| Year 13 | $30,910 | $14,599 | $467,551 |
| Year 14 | $29,932 | $15,577 | $451,975 |
| Year 15 | $28,889 | $16,620 | $435,355 |
| Year 16 | $27,776 | $17,733 | $417,622 |
| Year 17 | $26,588 | $18,921 | $398,701 |
| Year 18 | $25,321 | $20,188 | $378,514 |
| Year 19 | $23,969 | $21,540 | $356,974 |
| Year 20 | $22,527 | $22,982 | $333,992 |
| Year 21 | $20,987 | $24,521 | $309,470 |
| Year 22 | $19,345 | $26,164 | $283,307 |
| Year 23 | $17,593 | $27,916 | $255,391 |
| Year 24 | $15,723 | $29,785 | $225,605 |
| Year 25 | $13,729 | $31,780 | $193,825 |
| Year 26 | $11,600 | $33,909 | $159,916 |
| Year 27 | $9,329 | $36,180 | $123,737 |
| Year 28 | $6,906 | $38,603 | $85,134 |
| Year 29 | $4,321 | $41,188 | $43,946 |
| Year 30 | $1,563 | $43,946 | $0 |
Open the full version for HOA dues, mortgage insurance, extra payments, a printable copy, and a link you can send to someone.
Most used
Buying a home
What it costs each month, what you need up front, and what you can actually afford.
Monthly payment & amortization
Principal, interest, taxes, insurance, HOA and mortgage insurance in one number — plus the year-by-year schedule showing how much of it is still interest.
What would the monthly payment be?
How much home can I afford?
Works backwards from your income, your debts and the deposit you have, using the same debt-to-income limits a lender applies.
What price should I be shopping at?
What does a monthly budget buy?
The reverse calculator. Put in the payment you're comfortable with and it tells you the price range to shop in.
I can spend $X a month. What does that buy?
Cash to close
Deposit plus every line item a buyer pays at closing — lender fees, escrow and title, inspections, impounds — less any credit from the seller.
How much money do I need on the day?
Rent vs buy
Compares the true cost of both over time, counting appreciation, the cost of selling, and what the deposit would have earned if it stayed invested.
Am I better off renting?
Should I buy down the rate?
How long you have to keep the loan before the discount points pay for themselves.
Is paying points worth it?
When does PMI drop off?
The date the balance hits 80% of the original price (when you can ask) and 78% (when it must come off by law), and what an extra payment does to both.
How long am I paying mortgage insurance?
Refinance breakeven
Monthly saving against the cost of doing it — and an honest note about restarting the clock on a loan you're already years into.
Is it worth refinancing?
Selling a home
What a sale nets you, and what the tax bill looks like after it.
Seller net sheet
Every cost of a sale itemised — commission, escrow and title, transfer tax, repairs, the loan payoff — down to the cheque you actually get.
What would I walk away with?
How much equity can I use?
What a lender would let you take out at a given combined loan-to-value, and roughly what that would cost per month.
Can I borrow against the house?
California property tax & Prop 19
What the new home is taxed at from scratch, versus carrying your old Prop 13 base with you under Prop 19 — and the gap between the two over ten years.
What happens to my tax bill if I move?
Investing
Whether the numbers on a rental work before you write the offer.
Rental property returns
Net operating income, cap rate, cash-on-cash return, monthly cash flow and the break-even occupancy — with vacancy, maintenance and capital reserves taken out, not wished away.
Does this rental actually make money?
DSCR loan qualifier
Debt service coverage on the rent alone, the way an investor lender underwrites it, plus the largest loan that still clears their minimum.
Will the rent qualify for the loan?
1031 exchange vs selling outright
Capital gains, depreciation recapture and state tax on a straight sale, against deferring all of it into the next property — and what the difference buys with leverage.
What does the tax bill look like if I just sell?
Your business
The agent-side maths — what a closing actually pays you.