How Our Calculators Work

Data sources

Canadian data sources

US data sources

Calculation methodology

Income tax calculators

• Federal and provincial/state tax is calculated using progressive bracket schedules from official government sources.
• Standard deductions are applied automatically (federal standard deduction for the US; basic personal amount for Canada).
• CPP and EI are calculated at 2026 rates with annual maximums enforced.
• State-specific rules modelled for 2026 include the Connecticut personal tax credit (Table E) and exemption recapture, Minnesota's high-income standard deduction phase-down, Rhode Island's deduction and exemption phase-out, and Utah's taxpayer-credit phase-out. Where a state has not yet published a 2026 figure (Vermont standard deduction, Arizona indexed standard deduction) the 2025 or legislated amount is used and the page says so.
• Results are estimates — actual tax liability may differ based on additional deductions, credits, and individual circumstances.

Mortgage calculators

• Monthly payment is calculated using the standard amortization formula: M = P[r(1+r)^n] / [(1+r)^n − 1].
• Canadian mortgages use semi-annual compounding as required by the Interest Act (Canada). The quoted annual rate j is converted to the rate per payment period as r = (1 + j/2)^(2/k) − 1, where k is the number of payments per year (12 for monthly). Example: $500,000 at 5% over 25 years is $2,908.02 a month.
• US mortgages use monthly compounding.
• CMHC insurance premiums are applied automatically when the down payment is below 20% on Canadian mortgages where the tool models insurance.
• Stress-test qualification is shown at the higher of contract rate + 2% or 5.25% where the calculator includes stress-test context.
• Mortgage penalty (Canada): closed fixed = greater of 3 months' interest or the interest rate differential; variable = 3 months' interest. The lender selector follows each bank's published method: TD, RBC, Scotiabank and BMO compare your rate with the current posted rate for the closest term minus your original discount; CIBC calculates interest at your rate plus discount against its current posted rate; National Bank uses the posted rate at signing minus today's standard rate, plus one month of interest (max $500). Other lenders use a generic comparison rate. Estimates use simple interest, so banks that discount to present value quote slightly less.

RRSP / TFSA calculators

• Contribution room is based on federal limits published by the CRA.
• RRSP and FHSA tax refunds are the exact difference between income tax without and with the deduction (federal + provincial, including the Ontario surtax and Health Premium), not a single marginal rate.
• Growth projections use compound interest with annual compounding unless a tool specifies otherwise.
• Results do not account for pension adjustments or special RRSP situations.

Paycheck / take-home pay

• Canadian deductions: federal tax, provincial tax, CPP (5.95% up to the annual maximum, plus CPP2), EI (1.63% up to the annual maximum), using CRA 2026 payroll parameters (T4127).
• Quebec uses QPP instead of CPP where the calculator is Quebec-specific.
• US deductions: federal tax, state tax (each state's 2026 brackets, standard deduction or exemptions, and main personal credits), Social Security (6.2%), Medicare (1.45%). Local taxes are not included.
• Results are estimates — actual deductions may vary by employer, benefits, and filing status.

Social Security COLA 2027

• 2027 benefit = current monthly benefit × 1.036, rounded down to the whole dollar. SSA applies the COLA to the unrounded primary insurance amount, so the real figure can differ by about $1.
• Part B premium: 2026 amounts from the CMS notice (Federal Register 2025-20251), tier set by 2024 MAGI. 2027: the 2026 Medicare Trustees Report projection ($209.50) times the IRMAA multiple (1.4, 2.0, 2.6, 3.2 or 3.4 times the standard premium, i.e. 35–85% of Part B cost instead of 25%), tier set by 2025 MAGI against the 2026 brackets until CMS publishes the inflation-adjusted 2027 brackets. Replaced with CMS figures when announced.
• Hold-harmless: if the premium is deducted from benefits and no IRMAA applies in 2027, the premium increase is capped at the dollar COLA.
• Payment dates: second, third or fourth Wednesday by birth date, the 3rd for benefits that began before May 1997 or with SSI, and the 1st for SSI, moved to the previous business day for weekends and observed federal holidays. Checked against SSA Publication 05-10031.

2027 key numbers (Canada and US)

• Each figure is labelled Official (published by CRA, ESDC, IRS, SSA, CMS or HHS, or fixed in statute), Projected (with the name of the forecaster) or Pending (legislated or scheduled, no final number yet).
• Canadian projections apply CRA's indexation method: the change in the average all-items CPI for the 12 months to September, from Statistics Canada table 18-10-0004-01, applied to the 2026 amounts and rounded the way CRA rounds (nearest dollar; TFSA to the nearest $500 of the indexed $5,000 base).
• US projections are taken from named forecasters (Thomson Reuters Checkpoint, Milliman, Mercer, Evans Estate Law, Medicare Trustees); we do not publish our own guesses for IRS figures.
• Rows are replaced by official figures on the day of publication. Calculators keep 2026 values until then.

Bank of Canada rate decision and prime rate

• The policy rate comes from the Bank of Canada's daily target for the overnight rate (Valet series V39079) and prime from its weekly series of the major banks' prime rate (V80691311, from 1990). Announcement dates come from the Bank's published schedules.
• A GitHub Actions job checks the Bank's decision press releases about 20 minutes after each 9:45 ET announcement and every evening. A new rate is recorded from the press release the same day and confirmed by the daily series once it is published.
• Prime changes are dated to the Bank of Canada move that caused them. Until the weekly series catches up, a new prime is shown as the policy rate plus the current spread and labelled as estimated.
• The rate move calculator reuses our Canadian mortgage formula: monthly payments, semi-annual compounding, a new payment over the remaining amortization for adjustable-payment mortgages, and the change in the principal share for fixed-payment variable mortgages.

ACA subsidy calculator

• The benchmark is the second-lowest-cost silver plan offered in the county, taken from the CMS QHP Landscape file for HealthCare.gov states. Premiums for other ages use the CMS federal default age curve, or the state's own curve in Alabama, Mississippi, Oregon and Utah; only the three oldest children under 21 are rated.
• Premium tax credit = benchmark premium − household income × applicable percentage, using the IRS applicable percentage table for the coverage year and the prior year's HHS poverty guidelines. No credit above 400% of the poverty line.
• Medicaid eligibility is approximated at 138% of the poverty line in expansion states. Tobacco surcharges, ZIP-level service areas within a county and the dental share of premiums are not modelled.

Bronze vs Silver vs Gold (ACA plan comparison)

• Plans: every individual-market medical plan in the county from the CMS QHP Landscape file, with its deductibles (medical and separate drug, individual, family and per person), out-of-pocket maximums and the cost sharing for primary care, specialist, emergency room, inpatient facility and physician, and four drug tiers. Silver plans use the 94%, 87% or 73% cost-sharing reduction version up to 150%, 200% and 250% of the poverty line. Premiums and the premium tax credit follow the ACA subsidy calculator; the credit is not applied to catastrophic plans, which are shown only to households under 30 or with income below 100% or above 400% of the poverty line.
• Medical bills: AHRQ MEPS 2024 Full Year Consolidated file (HC-256), people under 65 with private coverage in all 12 months and no Medicare or Medicaid. Spending excludes dental and vision. People are grouped by age (0–17, 18–29, 30–44, 45–54, 55–64), self-rated health at the start of the year, any of 12 diagnosed chronic conditions and 4 or more prescription fills; groups with fewer than 120 people are widened. A planned birth or surgery uses people admitted to hospital for that reason (MEPS HC-254D). Each group is stored as weighted quantile bins of at least 11 people, never individual records. Dollars are raised to 2027 by 20.9%, the CMS Office of the Actuary projection of private health insurance spending per enrollee ($7,676 in 2024, $8,864 in 2026, +4.7% a year after).
• Simulation: 3,000 years per person drawn with a fixed seed, so the same inputs always give the same result. Office visits are split evenly between primary care and specialist copays; prescriptions take the generic tier up to $75 per fill on average, the specialty tier above $1,000 and the preferred-brand tier in between; outpatient and other care pays the plan's inpatient coinsurance after the deductible. Copays apply per visit, fill, stay or hospital day as the plan lists them, and spending stops at the per-person and family out-of-pocket maximums.
• Results: typical year is the median of premiums after subsidy plus out-of-pocket cost; bad year is the 90th percentile; worst case is premiums plus the out-of-pocket maximum. Networks, drug formularies, out-of-network care, HSA tax savings and tobacco surcharges are not modelled.

CRS calculator (Express Entry)

• Points follow the IRCC Comprehensive Ranking System criteria page (core, spouse, skill transferability and additional points, capped at 1,200). Points for arranged employment (job offers) are not awarded: IRCC removed them on March 25, 2025.

Student loan calculator

• Federal rates for loans first disbursed July 1, 2026 – June 30, 2027 come from the Department of Education's annual Federal Register notice.
• Repayment plans follow 34 CFR 685.208–685.209: the Repayment Assistance Plan (1–10% of AGI, $50 a month less per dependent, $10 minimum), the Tiered Standard plan (10–25 years by balance) and IBR for existing borrowers. The SAVE plan is no longer offered and is not modelled.

CPP, OAS and GIS

• OAS and GIS maximums and GIS income limits are the current-quarter amounts from Canada.ca and are updated every quarter (October–December 2026: OAS $762.50 at 65–74, GIS $1,138.90 for a single person).

Credit card comparisons

• Annual fees, interest rates and welcome offers are checked by hand on each issuer's own website; the page shows the date of the last check. An automated weekly check flags expired offers, broken issuer links and checks older than 100 days.

What our calculators don't include

• Income tax calculators do not model every possible deduction and credit (medical expenses, childcare, charitable donations, and so on).
• Mortgage calculators do not include property taxes, home insurance, condo fees, or closing costs unless the specific tool says otherwise.
• Paycheck calculators do not include employer benefit deductions, union dues, or pension plan contributions unless explicitly modeled.
• GIC calculators use illustrative rate ranges — actual rates vary by institution and change frequently.
• Some US state tax calculators use simplified assumptions where bracket structures are highly complex.

Accuracy & limitations

All calculators on Cashsembly are designed for educational and planning purposes. They use current official rates and standard calculation methods, but they cannot replicate the full complexity of individual tax situations. Results should not be used as a substitute for advice from a licensed accountant, tax professional, or mortgage broker. For your actual tax return, use CRA's official tools or certified tax software. For a mortgage, consult a licensed mortgage broker.

Automated rate updates

Cashsembly uses an automated data pipeline to keep mortgage rates current. Every Monday at 7:00 PM Toronto time, our system collects the latest rates from the Bank of Canada, RBC, TD, CIBC, and top mortgage brokers (Canada) and from Freddie Mac and the Federal Reserve (United States). Rates are automatically published to the site without manual intervention. Tax brackets and contribution limits are updated annually when the CRA and IRS publish official figures.

The extended per-lender comparison on the Canadian mortgage rates page is shown only when its data is less than 7 days old. It has been paused since May 2026 and stays hidden until it can be fed from lenders' own published rates; the main bank rates table is refreshed weekly and shows its "as of" date.

Feedback & corrections

Found an error or outdated rate? We take data accuracy seriously. Please contact us at info@cashsembly.com or use the contact form. We review all submissions and typically correct verified errors within 48 hours.