King County Mortgage Calculator
On the King County median home price of $811,000, a 20%-down, 30-year loan at today's 6.47% rate runs about $4,802/month — $4,088 principal & interest, $568 property tax at King County's 0.84% effective rate, and $146 homeowners insurance. That is about $61/month more than the Washington state-average tax rate would cost on the same home. Enter your own price and down payment below.
$4,802 /mo
P&I: $4,088 · Tax: $568 · Insurance: $146
Loan amount: $648,800 · Total interest: $822,903
Yearly amortization schedule
| Year | Interest | Principal | PMI | Balance |
|---|---|---|---|---|
| 1 | $41,764 | $7,293 | — | $641,507 |
| 2 | $41,277 | $7,779 | — | $633,728 |
| 3 | $40,759 | $8,298 | — | $625,430 |
| 4 | $40,206 | $8,851 | — | $616,579 |
| 5 | $39,616 | $9,441 | — | $607,138 |
| 6 | $38,987 | $10,070 | — | $597,068 |
| 7 | $38,315 | $10,741 | — | $586,327 |
| 8 | $37,600 | $11,457 | — | $574,869 |
| 9 | $36,836 | $12,221 | — | $562,648 |
| 10 | $36,021 | $13,035 | — | $549,613 |
| 11 | $35,152 | $13,904 | — | $535,709 |
| 12 | $34,226 | $14,831 | — | $520,878 |
| 13 | $33,237 | $15,820 | — | $505,058 |
| 14 | $32,183 | $16,874 | — | $488,184 |
| 15 | $31,058 | $17,999 | — | $470,185 |
| 16 | $29,858 | $19,199 | — | $450,986 |
| 17 | $28,579 | $20,478 | — | $430,508 |
| 18 | $27,214 | $21,843 | — | $408,665 |
| 19 | $25,758 | $23,299 | — | $385,366 |
| 20 | $24,205 | $24,852 | — | $360,514 |
| 21 | $22,548 | $26,508 | — | $334,006 |
| 22 | $20,781 | $28,275 | — | $305,730 |
| 23 | $18,897 | $30,160 | — | $275,570 |
| 24 | $16,887 | $32,170 | — | $243,400 |
| 25 | $14,742 | $34,315 | — | $209,086 |
| 26 | $12,455 | $36,602 | — | $172,484 |
| 27 | $10,015 | $39,041 | — | $133,443 |
| 28 | $7,413 | $41,644 | — | $91,799 |
| 29 | $4,638 | $44,419 | — | $47,380 |
| 30 | $1,677 | $47,380 | — | $0 |
Rates: Freddie Mac PMMS (wk 2026-06-18). Property tax: Tax Foundation. Insurance: Insurance.com. PMI applies when your down payment is under 20% (LTV > 80%). You can request cancellation at 80% LTV; the servicer must auto-terminate it at 78% (Homeowners Protection Act). How we calculate →
Monthly payment breakdown for a King County home
At the King County median home price of $811,000, a conventional 30-year loan at 6.47% with 20% down splits into: $4,088 principal & interest, $568 property tax, and $146 homeowners insurance — a total PITI of $4,802/month.
The property tax line uses King County's real effective rate of 0.84% (median tax bill of $6,785 on a median home value of $811,200, US Census ACS), not a generic national average — so this figure reflects what King County actually charges, before any local exemption.
King County vs the Washington state average property tax rate
King County's 0.84% effective property tax rate is above Washington's 0.75% state average. On the same $811,000 home, that difference works out to $61/month more in the tax line of the mortgage payment compared with paying the Washington average rate instead of King County's.
Property tax is set locally — by the county, city and school district — so the state average is only a rough guide. Two otherwise identical Washington homes in different counties can carry meaningfully different monthly payments purely because of where the tax rate lands.
What the King County median buys vs a $400,000 national budget
A $400,000 home taxed at King County's 0.84% rate and insured at Washington's average would run about $2,442/month — $2,359 less than the King County county median payment of $4,802/month, since King County's median home price ($811,000) is $411,000 above the $400,000 reference used elsewhere on this site.
In other words, price — not tax rate — usually drives the biggest gap between a King County payment and a generic national estimate. Use the calculator above to swap in your own target price.
PMI in King County if you put down less than 20%
Putting 10% down instead of 20% on the same $811,000 King County home adds private mortgage insurance (PMI) of about $487/month, bringing the total payment to roughly $5,799/month instead of $4,802. PMI is required on conventional loans below 20% down and cancels automatically once your loan balance reaches 78% of the original price.
King County mortgage — frequently asked questions
How much is a mortgage payment in King County?
On the King County median home price of $811,000, a 20%-down 30-year loan at 6.47% runs about $4,802/month total (principal, interest, property tax and insurance).
What is the property tax on the median home in King County?
King County's effective property tax rate is 0.84%, which works out to about $568/month ($6,812/year) on the $811,000 county median home value.
How does King County property tax compare to the rest of Washington?
King County's 0.84% effective rate is above the Washington state average of 0.75%, a difference of about $61/month on a $811,000 home.
What income do I need to afford a home in King County?
Using the common 28%-of-gross-income guideline against the $4,802/month PITI payment on the King County median home, that implies a gross annual income of roughly $205,794.
How much does PMI cost in King County with less than 20% down?
Putting 10% down on the $811,000 King County median home adds about $487/month in PMI, for a total payment near $5,799/month instead of $4,802.
What's included in a King County mortgage payment?
PITI: principal and interest together $4,088, property tax $568 at King County's 0.84% rate, and homeowners insurance $146 at the Washington state average — no HOA dues assumed unless you add them above.
More Washington counties in this pilot
Washington mortgage calculator · King County property tax deep-dive — the full county-by-county property tax breakdown behind this payment estimate.
Mortgage calculators in other pilot counties
Researched & verified by the Calcuris Data & Research Team. How we build and check our tools →