Methodology

How the calculators work, where the numbers come from, and what an estimate leaves out.

Where the figures come from

Tax figures are taken from published IRS guidance and kept in data files, never written into the calculator code. When a threshold changes, one data file is updated and every page that uses it changes with it. Each figure is cited on the sourcespage, and each calculator shows when its figures were last verified.

Overtime Tax Deduction Calculator

  1. Premium per hour. Only the premium portion of overtime pay qualifies — the extra half of time-and-a-half required under section 7 of the Fair Labor Standards Act. The calculator takes half of your regular hourly rate.
  2. Qualified overtime. The premium per hour multiplied by your overtime hours for the year.
  3. Annual cap. The deduction is capped at $12,500 for single filers and heads of household and $25,000 for married couples filing jointly. Married filing separately is not eligible.
  4. Income phase-out. Above $150,000 of income ($300,000 for joint filers) the deduction is reduced by $100 for every full $1,000 over the threshold. A partial thousand is rounded down, as line 19 of Schedule 1-A instructs. It cannot go below zero.
  5. Estimated saving. The deductible amount multiplied by your marginal federal rate. That rate is looked up on taxable income — your income less the standard deduction for your filing status — using the 2026 federal brackets.

Tax Refund Calculator With Overtime

  1. Deduction. The same cap and income phase-out as the Overtime Tax Deduction Calculator, from one shared function, so the two pages always agree.
  2. Taxable income. Total income, less the standard deduction, less the overtime deduction, never below zero.
  3. Tax. Worked bracket by bracket through the 2026 tables in Rev. Proc. 2025-32, to the cent, then reduced by any credits entered. Credits cannot take the tax below zero.
  4. Refund. Federal tax withheld minus tax owed. A negative result is a balance due. The overtime deduction's effect is the refund with it minus the refund without it.

Total income is used as modified adjusted gross income for the phase-out; the IRS defines the exact measure in Notice 2025-69. The estimate is federal only and leaves out state tax, self-employment tax and refundable credits. It covers tax year 2026 only.

No Tax on Tips Calculator

  1. Eligibility. The occupation must be on the IRS list of tipped occupations; married filing separately and a specified service trade or business are not eligible.
  2. Tips counted. Your qualified tips, limited to net profit from the business for the self-employed when you enter it.
  3. Cap and phase-out. The smaller of that and $25,000, less $100 for each full $1,000 of income over $150,000 ($300,000 married filing jointly), as on Schedule 1-A Part II. The same phase-out function serves the overtime deduction.
  4. Tax saving. Federal income tax worked through the 2026 brackets with the standard deduction, once without the deduction and once with it; the saving is the difference. Credits, state tax, Social Security and Medicare are not included.

Overtime Pay Calculator

  1. Rates. Time and a half is the hourly rate × 1.5, double time × 2, worked to the cent.
  2. Hours. Either the hours you enter in each category, or total hours for the week split at 40: up to 40 at the regular rate, the rest at time and a half, the federal (FLSA) weekly rule. State daily overtime is not modeled; enter it in the categories yourself.
  3. Pay. Regular, overtime and double-time pay for the week, then × 52 for a year and ÷ your pay periods per paycheck. It assumes every week is the same.
  4. Qualified premium. The hourly rate × 0.5 for each overtime or double-time hour, counting only hours over 40 in the week, the same premium the overtime deduction calculator uses. The link to that calculator passes the rate and a year of these hours.

Mortgage Recast Calculator

  1. New balance. Your balance less the lump sum. A lump sum larger than the balance pays the loan off and there is nothing to recast.
  2. New payment. The standard monthly amortization formula on the new balance, over the same remaining months at the same rate. All arithmetic is in whole cents, so a 360-payment schedule cannot drift.
  3. Interest saved. Total interest over the remaining term before the recast, less total interest after it.
  4. Fee payback. The recast fee divided by the monthly reduction, rounded up to whole months. Under 12 months is treated as worth it — a rule of thumb, not a lender rule.
  5. Extra-payment comparison. The same lump sum paid straight to principal keeps the payment and shortens the term instead.

Fees, minimum lump sums and which loan types can be recast are planning defaults drawn from published lender guidance. They are not a legal rule and not the policy of any one servicer, so the calculator asks you to confirm them with yours.

Recast vs Refinance Calculator

  1. Recast side. The same engine as the Mortgage Recast Calculator, so the two pages always agree.
  2. Refinance side. A cash-in refinance: the same lump sum reduces the balance, and the remainder is refinanced at the new rate over the same remaining months. Closing costs are paid in cash rather than rolled into the loan. This keeps both routes on the same cash and the same term, so the comparison is like for like.
  3. Total cost. The lump sum, the fee or closing costs, and every monthly payment over the remaining term.
  4. Break-even. The extra upfront cost of the refinance divided by how much lower its payment is, rounded up to whole months. It is shown only when the refinance payment is lower.

A real refinance can also change the term, roll in cash-out or costs, or affect tax and insurance escrow, none of which is modelled. The lender comparison uses only what each lender publishes on its own website. Where a figure is not published it is marked "Not published" and is never estimated.

Texas Vehicle Tax, Title and License Calculator

  1. Taxable amount. The purchase price minus any trade-in allowance, never below zero. The engine reads how a state treats a trade-in from that state's data file, so other states can tax the full price or cap the credit.
  2. Sales tax. The taxable amount multiplied by 6.25%, rounded to the cent. This is the one exact figure in the estimate.
  3. Title and registration. These vary by county, so they are shown as ranges: a title fee of $28 or $33, a base registration fee of $50.75 for cars and light trucks, and local county fees of up to $31.50.
  4. Private-party sales. Texas taxes the greater of the price paid or 80% of the vehicle's Standard Presumptive Value. SPV values are not built in, so an estimate without one carries a warning that the real tax could be higher.

The total is shown as a range. Verify title and local fees with your county tax assessor-collector's office.

A known interpretive gap: trade-ins on private-party sales

On a private-party sale the Texas Comptroller taxes the greater of the sales price (total consideration) or 80% of the vehicle's SPV, and says SPV procedures may apply to the taxable value of the vehicle bought but not to the value of the trade-in. Neither page says whether the 80%-of-SPV comparison is made before or after a trade-in is subtracted. We compare 80% of the SPV with the price beforethe trade-in, then subtract the trade-in from the greater figure. That is our reading, not a rule the Comptroller states, so whenever a trade-in and the SPV floor both apply to the same private sale the calculator says the figure is directional and to confirm it with your county tax office. The two pages:Texas Comptroller — Trade-Ins (Motor Vehicle Tax Guide) and Texas Comptroller — Standard Presumptive Value (Motor Vehicle Tax Guide).

California Vehicle Tax, Title and License Calculator

  1. Sales tax. The full price multiplied by the statewide rate plus the district tax you enter, rounded to the cent. A trade-in does not reduce the price: CDTFA's dealer guide says the allowance cannot be excluded. Until you enter a district rate the estimate uses the state rate only and says so.
  2. Fixed DMV fees. The registration fee (which includes a $3 alternative fuel/technology fee), the CHP fee and the title fee. The title fee was last confirmed at $25 in January 2023, before DMV's yearly CPI increases, and DMV's current fees page lists $28 for a replacement title, so it is shown as a $25 to $28 range.
  3. Value-based DMV fees. The vehicle license fee is 0.65% of value, and the transportation improvement fee is a flat amount for the value band the vehicle falls in. DMV decides the value; the calculator uses your purchase price.
  4. Left out. County and district registration fees, dealer documentation fees, the road improvement fee for some zero-emission vehicles, and private-party purchases. Each is listed on the page rather than estimated.

New York Vehicle Tax, Title and License Calculator

  1. Sales tax. The taxed price multiplied by the 4% state rate plus your county's rate from Publication 718, rounded to the cent. New York works the rate out where the buyer lives, so the county you choose sets it. Until you choose one, the estimate uses the state rate only and says so.
  2. Trade-in. On a dealer sale the trade-in is subtracted from the taxed price. New York's dealer guide allows that only if the dealer intends to resell the vehicle, and it is a 2012 edition, so the page says to check current guidance.
  3. Registration. The DMV's two-year fee from its weight chart, using the weight you enter. Without a weight, the fee is shown as the range across the chart, $26.00 to $140.00.
  4. County use tax and MCTD fee. From the DMV's county chart, by county and weight, for two years. A county that is not on the chart shows no county use tax.
  5. Title and plates. $50 for the title certificate and $25 for plates, as the DMV lists them.
  6. Left out. Dealer charges such as documentation fees, and private-party purchases, where the DMV collects the sales tax.

Florida Car Sales Tax Calculator

  1. Sales tax. 6% of the taxable amount, plus your county's 2026 surtax on the first $5,000 of it, rounded to the cent. The county comes from the Department of Revenue's DR-15DSS table. Until you choose one, the estimate uses the state rate only and says so.
  2. Trade-in and the $5,000 cap. A qualifying trade-in is subtracted first, and the $5,000 surtax cap is applied to what is left. The Department of Revenue says the surtax applies to the first $5,000 of the purchase price but does not spell out how that combines with a trade-in. The difference only arises when the trade-in takes the taxable amount below $5,000, and is at most $100 (2% of $5,000).
  3. Title. $75.25 ($70 + $1 + $4.25, Fla. Stat. 319.32), plus $2.50 if you choose a mailed paper title.
  4. Registration. The annual license tax by weight band (Fla. Stat. 320.08), shown as the $14.50 to $32.50 range if no weight is entered, and the $225 initial registration fee (Fla. Stat. 320.072), included unless you switch it off.
  5. Left out. Other registration fees and service charges, which we could not verify, and dealer charges.

Georgia TAVT Calculator

  1. Value taxed. For a new vehicle, the greater of the price and the Georgia DOR fair market value you enter. For a used vehicle or a private sale, the DOR value. If you leave the value blank, the estimate uses your price and says so.
  2. Trade-in. Subtracted from the value on a dealer sale only, as the DOR TAVT FAQ describes.
  3. TAVT. 7.0% of what is left, rounded to the cent. The 3% new-resident rate is described on the page but not applied.
  4. Fees. The $18 title fee and the $20 passenger car tag from the DOR fee page. Late penalties and specialty plates are left out.

North Carolina Car Tax and Tag Calculator

  1. Highway use tax. On a dealer sale, 3% of the price less the trade-in. Include any administrative or document fee in the price, as MVR-106 does. On a private sale, 3% of the NCDMV value you enter, with no trade-in. Without that value, the estimate uses your price and says so.
  2. Fees. The $66.75 title and $46.25 passenger plate from the MVR-94 fee schedule, plus $17 in Durham, Orange and Wake counties and $1 in Randolph. Until you choose a county, the county part is shown as a $0 to $17 range.
  3. Left out. Annual vehicle property tax, which counties bill with renewal, other plate classes and the $250 new-resident cap.

Pennsylvania Car Sales Tax Calculator

  1. Sales tax. 6% of the price less any trade-in taken by the seller, plus 1% for Allegheny County residents or 2% for City of Philadelphia residents, rounded to the cent. Until you choose a county, the estimate uses 6% and says so.
  2. Fees. The $72 title and the $48 one-year passenger registration from PennDOT's MV-70S (April 2026), plus $5 in the 27 counties on PennDOT's fee for local use list, and the $36 lien fee if you switch it on.
  3. Left out. Agent processing fees, specialty plates, plate transfers and the electric vehicle road user charge.

Washington Car Sales Tax Calculator

  1. Sales tax. The price less any like-kind trade-in, multiplied by 7% (the 6.5% state rate plus the 0.5% motor vehicle sales tax) plus the local rate you enter from the DOR table, rounded to the cent. Without a local rate, the estimate uses 7% and says so.
  2. Fees. The $56.50 title with registration ($15 + $12.50 + $29), the $30 tab fee, $10 additional weight fee and $0.75 license service fee, and the RCW 46.17.365 weight fee by weight ($35, $65 or $82.50). A new vehicle adds two original plates at $52 each.
  3. Left out. The RTA excise tax, transportation benefit district, emergency medical services and electric vehicle fees, and the out-of-state fee.

Arizona Car Sales Tax and VLT Calculator

  1. Sales tax. The price less any trade-in, multiplied by 5.6% (A.R.S. 42-5010 and 42-5010.01) plus the local rate you enter, rounded to the cent. Without a local rate, the estimate uses 5.6% and says so.
  2. Vehicle license tax. 60% of the MSRP, reduced by 16.25% for each full year since first registration, divided by 100 and multiplied by $2.80 for a new vehicle or $2.89 otherwise, with a $10 minimum (A.R.S. 28-5801). For a new vehicle without an MSRP, the price is used; for a used vehicle without one, the VLT is left out and the result says so.
  3. Fees. $4 title and $8 registration (A.R.S. 28-2003) and the $1.50 air quality fee (A.R.S. 49-551).
  4. Left out. Emissions test fees, specialty plates, fees for alternative-fuel vehicles, and private sales.

Michigan Car Sales Tax Calculator

  1. Sales tax. 6% of the price less the trade-in allowance: for 2026, the trade-in value or $12,000, whichever is less, on a purchase from a licensed dealer (Form 485). On a private sale, 6% of the full price. Rounded to the cent.
  2. Fees. The $15 title transfer fee and the $5 first-time standard plate.
  3. Left out. The registration fee, which is set from the MSRP and age; plate transfers; the Recreation Passport; and specialty plates.

Illinois Car Sales Tax Calculator

  1. Dealer sale. The price less any qualified trade-in (no cap since 2022), multiplied by 6.25% plus the local rate you enter, rounded to the cent. Without a local rate, the estimate uses 6.25% and says so.
  2. Private sale. The flat amount from IDOR's RUT-5 chart for 2026: by model year under $15,000, by price at $15,000 or more. Without a model year, the newest-year amount ($465) is used and the result says so. No trade-in deduction.
  3. Fees. The $165 title and $151 passenger registration, as published by the Secretary of State.
  4. Left out. Local private party taxes (Chicago, Cook County and others), the extra RTA or Metro-East use tax some buyers owe, and lien, electric vehicle and specialty plate fees.

Mortgage, Extra Payment, Amortization Schedule and Payoff Calculators

  1. Payment. Principal and interest = loan × r ÷ (1 − (1 + r)^−n), where r is the annual rate ÷ 12 and n the number of monthly payments, rounded to the cent. Property tax and insurance are the yearly amounts you enter ÷ 12; PMI and HOA are the monthly amounts you enter.
  2. Schedule. Each month, interest = balance × r, rounded to the cent; principal = payment − interest; any extra goes to principal. The last scheduled payment clears what rounding leaves, so the balance ends at exactly zero.
  3. PMI dates. The first payment after which the scheduled balance is at or below 80% (cancel on request) and 78% (automatic end) of the price, following the CFPB's description of the rules. With 20% or more down, none are shown.
  4. Payoff. The balance is run forward at your payment, plus any extra, until it reaches zero. A payment that does not cover the first month's interest is reported as never paying off. The extra needed for a target is the payment for that term less your current payment.

Reporting

From tax year 2026 employers report qualified overtime separately on W-2, box 12, code TT. You claim the deduction on Schedule 1-A (Form 1040). It does not require you to itemize.

What an estimate leaves out

Corrections

If a figure looks wrong, please tell us. Corrections are checked against the source and published with the new verification date.