Every mortgage calculator shows you principal and interest. Then the tax bill arrives, the roof ages, the insurance renews on a shoreline policy — and the real number turns out to be somewhere else entirely. This one shows the whole picture.
• RI Oil Prices · CheapestOil · NewEnglandOil — dealer prices by ZIP, updated daily
• RI Office of Energy Resources — the state’s own price series
• RI Public Utilities Commission — electric rates
Your own delivery ticket beats all of them.
How the maintenance number is figured
Most calculators either ignore maintenance or apply the old rule of thumb: one percent of the purchase price a year. That rule breaks badly in Rhode Island, and it breaks in opposite directions depending on where you are.
Roofs, furnaces and siding belong to the building. Land needs nothing. On Block Island or in Little Compton, where most of the price is the lot, one percent of price wildly overstates what the house will cost to keep. In Woonsocket or Central Falls, where a home sells for close to what it would cost to rebuild, the same rule understates it.
This tool separates the two. It estimates what your house would cost to rebuild — its square footage times a rebuild cost per foot, adjusted for condition — treats the remainder of the price as land, and sets a reserve against the building alone. Older houses reserve more, because more of their components are due. Coastal exposure raises it, because salt air is hard on everything it touches, and in this state very little is far from salt water.
It is an estimate, and an estimate is all it can be from a price and a town. Enter your assessor’s own land and building values and it stops estimating.
Three things that make Rhode Island different
Assessment runs at about 100% of market value, not the 70% used next door in Connecticut. A Rhode Island rate of $12 per $1,000 and a Connecticut rate of 12 mills are not the same tax — the Rhode Island one is roughly 40% heavier on an identical house. Comparing the two states rate-to-rate is the single most common mistake we see buyers make on this border.
Fire districts bill separately, and they are everywhere. Across much of the state a parcel sits inside a fire district that levies its own rate per $1,000 on top of the town’s. It arrives as its own bill, so buyers reading only the town rate underestimate their tax. Enter the district rate and the tax line recalculates. If you leave it at zero, the result panel says so.
The “Taylor Swift Tax” catches second homes over $1 million. Rhode Island’s non-owner-occupied property tax charges $5 per $1,000 of assessed value above $1 million on residential property that is neither a primary residence nor rented for 183 or more days a year. Only the portion above the threshold is taxed, so a $3 million second home owes roughly $10,000 a year. Tick the box in the form and it appears in the payment stack. Its effective date and administration were still being settled, so treat the figure as an estimate and take it to a tax professional before you rely on it.
What updates itself here, and what doesn’t
Almost nothing. This tool runs entirely in your browser with no service behind it, so the interest rate, the fuel prices and the electric rate are figures we typed in and revise by hand. They were set in August 2026. Nothing reaches out for a live quote.
That matters most for the interest rate, which moves weekly. The default is the Freddie Mac national 30-year average — a placeholder for arithmetic, not a rate anyone has offered you. Put your lender’s actual quote in the box.
The tax rates underneath are Rhode Island Division of Municipal Finance figures for FY 2026, on the 2025 tax roll. Municipalities set new rates each year, so some will have moved on. Every result panel says which vintage it used.
Why energy sits in its own band
No lender underwrites your electric bill, so folding it into the payment would make this number impossible to compare against the quote your loan officer hands you. It sits below the payment instead, with its own subtotal and an all-in figure underneath.
It belongs on the page all the same. Rhode Island carries some of the highest electricity rates in the country, and roughly a quarter of the state’s homes still heat with oil. Heating fuel alone can differ by thousands of dollars a year between two houses of the same size on the same street — one on natural gas, one on propane.
The heating estimate works from the square footage and age of the house rather than a flat guess, then converts that demand through the efficiency of whatever system you pick. Geothermal moves roughly four units of heat per unit of electricity, air-source about two and a half, and electric baseboard exactly one — which is why baseboard heat here is punishing, and why it belongs on the page before you buy rather than after.
Almost the whole state buys electricity from RI Energy, with two exceptions worth knowing: Pascoag Utility District serves part of Burrillville, and Block Island Power Company serves New Shoreham on its own rates. Pick either town and the result panel links you to the right utility.
What we left out, and why it’s yours to add
Snow removal, lawn care, water and sewer, septic, trash, internet — none of these are in the payment or the energy band, and they shouldn’t be assumed. Half the people reading this mow their own lawn. The other half write a cheque every month. So they sit in a third band you switch on line by line, with figures you can overwrite.
There is a structural reason they were missing. The maintenance reserve is calculated on the building, because roofs and furnaces belong to the house and not to the dirt. But mowing and plowing scale with the lot — the exact opposite.
Flood insurance starts at zero deliberately, and in this state that blank is the one to take seriously. A homeowners policy never covers flood. On a coastal parcel a policy can run into four figures a year, and it is mandatory with a federally backed mortgage in a Special Flood Hazard Area. There is no honest default — check the flood map for the address and get a quote.
Check every number here yourself
Nothing on this page updates on its own, so here is where each assumption comes from and how fast it goes stale.
Interest rate — moves weekly.
Freddie Mac Primary Mortgage Market Survey, published Thursdays. Your lender’s quote beats the national average.
Heating oil and propane — moves daily, and dealer to dealer.
The state publishes its own series at the RI Office of Energy Resources, and the federal weekly survey is EIA’s Rhode Island page — collected October through March and paused for the summer. For live dealer quotes by ZIP, compare RI Oil Prices, CheapestOil or NewEnglandOil. The spread between dealers is usually worth the ten minutes.
Electricity — rates reset on a filed schedule.
RI Public Utilities Commission for approved rates and pending filings. On Block Island or in Pascoag, use that utility’s published rate instead.
Tax rates, fire districts and revaluation years — set annually.
RI Division of Municipal Finance publishes the statewide table. Fire district rates come from the district or the town tax collector, and the assessor will tell you which district an address falls in.
Land and building values — change only at revaluation.
Vision’s Rhode Island directory covers 20 municipalities; the state’s own land and tax records directory covers all 39. These are the exact figures the tool would rather use than its own estimate.
Insurance and rebuild cost — no public source worth quoting.
Insurance is modeled here from structure value and water exposure. On the Rhode Island shore especially, wind deductibles and flood coverage move it enough that only a real quote means anything. Ask us and we’ll get you one.
Information deemed reliable but not guaranteed. Every figure produced by this tool is an estimate built from public data and general assumptions. It is not an appraisal, a loan estimate, an insurance quote, or a tax determination, and no part of it creates a professional relationship or a representation of fact. Seaport Real Estate Services and Seaport Advisory make no warranty, express or implied, as to the accuracy or completeness of anything shown here, and accept no liability for any decision made in reliance on it. Verify property tax with the town assessor, financing with your lender, insurance with a licensed agent, and tax treatment with a CPA or attorney before you act on any number. Estimates are general guidance only. Property tax depends on the specific parcel, its assessment, exemptions, and any fire-district levies; confirm with the town assessor. Insurance figures are modeled from structure value and water exposure and are no substitute for a quote. Maintenance reserves are planning estimates, not predictions. Tax rates are RI Division of Municipal Finance FY 2026 residential rates on the 2025 tax roll, applied at approximately 100% of assessed value. Some municipalities levy additional fire-district taxes and a few use tiered residential rates. Median selling prices and median home sizes reflect current Market Pulse data. Homes over $1M that are not owner-occupied may owe the state Non-Owner Occupied Property Tax; its effective date and administration were still being finalised. Not tax, legal, or insurance advice.