Sources
Every figure in the calculators traces to published guidance. This is the full list.
Overtime deduction rules, caps and phase-out
- IRS — What to know about the No Tax on Overtime deduction
- IRS Fact Sheet FS-2026-13
- IRS Schedule 1-A (Form 1040), Part III — No Tax on Overtime (2025 form)
Last verified September 18, 2026.
Federal tax brackets, 2026
Last verified September 18, 2026.
Standard deduction, 2026
Last verified September 19, 2026.
Tax refund with the overtime deduction (2026)
- IRS — What to know about the No Tax on Overtime deduction
- IRS — Questions and answers about the deduction for qualified overtime compensation
- IRS — Schedule 1-A (Form 1040), Part III, No Tax on Overtime (2025 form)
- IRS — How to update withholding to account for tax law changes for 2025
- IRS — General Instructions for Forms W-2 and W-3 (2026), box 12 code TT
- IRS Rev. Proc. 2025-32 (2026 tax rates and standard deduction)
Last verified September 24, 2026. IRS primary sources. Where the IRS has not stated a rule, such as employer withholding for the 2026 W-4, the calculator page says so.
No tax on tips: the qualified tips deduction
- IRS — What the “No Tax on Tips” deduction means for you
- IRS — Occupations that customarily and regularly received tips on or before Dec. 31, 2024
- IRS — Final regulations listing tipped occupations (IR-2026-49, April 10, 2026)
- IRS — Working Families Tax Cuts: individuals and workers (SSTB rule, tax years)
- IRS — Schedule 1-A (Form 1040), Part II, No Tax on Tips
- IRS — General Instructions for Forms W-2 and W-3 (2026), box 12 code TP and box 14b
- IRS — Tip recordkeeping and reporting (Social Security and Medicare)
- IRS — Topic no. 761, Tips: withholding and reporting
- IRS Rev. Proc. 2025-32 (2026 tax rates and standard deduction)
Last verified October 18, 2026. IRS pages only: the deduction rules, the list of tipped occupations, Schedule 1-A, the 2026 W-2 instructions and tip reporting.
Overtime pay: time and a half, double time and the regular rate
- US Department of Labor, Wage and Hour Division — Overtime Pay
- US Department of Labor — Fact Sheet #23: Overtime Pay Requirements of the FLSA (revised October 2019)
- 29 CFR 778.208, Inclusion and exclusion of bonuses in computing the regular rate (7-1-25 edition, govinfo.gov)
- IRS — What to know about the No Tax on Overtime deduction
- California Labor Commissioner — Overtime FAQ (daily overtime and double time)
Last verified September 27, 2026. US Department of Labor guidance and federal regulations for the FLSA weekly overtime rule, the IRS for the deduction, and California's Labor Commissioner for its daily overtime rule.
Mortgage recast: fees, minimum lump sums and loan-type eligibility
- Fannie Mae Servicing Guide — C-1.2-01, Processing Additional Principal Payments (re-amortization after a principal curtailment)
- Freddie Mac Single-Family Seller/Servicer Guide — Section 8103.3(d), Partial prepayments (curtailments) and P&I recast
- CFPB — Your mortgage servicer must comply with federal rules (extra payments toward principal)
- Amerisave — Recasting a mortgage: what it means and how it works
- JVM Lending — What is a mortgage recast?
Last verified September 19, 2026. Fannie Mae, Freddie Mac and the CFPB set out how a recast and extra principal payments work. The fee range and minimum lump sum are planning figures from published lender guides, not an agency rule; each servicer sets its own.
Lender recast policies: Chase, Wells Fargo and Bank of America
- Chase — Recast your mortgage loan
- Chase — What is a mortgage recast?
- Wells Fargo — Maximizing cash flow while buying a home
- Wells Fargo — Jumbo loan
- Bank of America — Mortgage FAQs ("Recast your existing mortgage")
Last verified September 24, 2026. These are each lender's own pages, read on the date shown. Where a lender does not publish a figure, the calculator page says so rather than estimating it.
California vehicle tax, title and license
- CDTFA — Sales and use tax rates (statewide rate and district taxes)
- CDTFA — CDTFA-95, California Sales and Use Tax Rates by County and City (operative October 1, 2026)
- CDTFA — Publication 34, Motor Vehicle Dealers (trade-ins, October 2025)
- California DMV — Registration fees (registration, CHP, VLF and TIF)
- California DMV — Vehicle Industry News VIN 2023-02, Miscellaneous Fee Increases (title fee)
- California DMV — Vehicle registration fee calculator (dealer documentation fee limit)
Last verified September 25, 2026. State agency sources only. The title fee was last confirmed in January 2023 and is shown as a range, and county and district registration fees were not found on the DMV pages read, so the calculator says so instead of estimating them.
New York vehicle tax, title and license
- New York DMV — Passenger vehicle registration fees, use taxes and supplemental fees (fee chart, county use tax, title and plate fees)
- New York Tax & Finance — Publication 718, sales and use tax rates by jurisdiction (effective March 1, 2025)
- New York Tax & Finance — Sales tax rates by local taxing jurisdiction for current periods
- New York Tax & Finance — Motor vehicles, vessels, and trailers (tax uses the buyer's home rate)
- New York Tax & Finance — Sales tax rates, additional sales taxes, and fees (4% state rate, MCTD)
- New York Tax & Finance — Publication 838, A Guide to Sales Tax for Automobile Dealers (trade-ins, 2012 edition)
- New York DMV — Sales tax information (who collects tax on private sales)
Last verified September 25, 2026. State agency sources only. County sales tax rates are from Publication 718, effective March 1, 2025, which New York lists as its current edition. The trade-in guidance comes from a 2012 dealer guide, so the calculator page says to check current guidance.
Florida car sales tax, title and registration
- Florida DOR — Sales and Use Tax on Motor Vehicles (GT-800030)
- Florida DOR — Discretionary Sales Surtax Information for Calendar Year 2026 (DR-15DSS)
- Florida Statutes 2026 — s. 319.32, certificate of title fees
- Florida Statutes 2026 — s. 320.072, initial registration fee
- Florida Statutes 2026 — s. 320.08, license taxes
Last verified September 27, 2026. Florida Department of Revenue publications and the 2026 Florida Statutes. Registration fees and service charges beyond the license tax could not be verified, so the calculator page says so instead of estimating them.
Georgia TAVT, title and tag
- Georgia DOR — Vehicle Taxes: Title Ad Valorem Tax (TAVT) and Annual Ad Valorem Tax
- Georgia DOR — Title Ad Valorem Tax (TAVT) FAQ
- Georgia DOR — Motor Vehicles Fees, Fines, and Penalties
- Georgia DOR — New to Georgia?
Last verified October 18, 2026. Georgia Department of Revenue pages only. The fair market value comes from the DOR assessment manual, so the calculator asks you to look it up with the DOR estimator instead of guessing it.
North Carolina highway use tax, title and registration
- NCDMV — Fee Schedule, MVR-94 (effective July 1, 2024; rev. 9/26)
- NCDMV — Requirements for Obtaining North Carolina Registration, MVR-106 (rev. 04/26): highway use tax
- NCDOT — NCDMV fees to increase July 1, 2024
- NCDMV — Vehicle Titles
Last verified October 18, 2026. NCDMV forms and NCDOT pages only. MVR-106 lists Orange County's regional transit tax as $8 while the newer MVR-94 fee schedule lists $10, so the calculator uses the fee schedule and the page says so. Annual vehicle property tax is not modeled.
Pennsylvania vehicle sales tax, title and registration
- PennDOT — Bureau of Motor Vehicles Schedule of Fees, MV-70S (4-26)
- PennDOT — Buying and Selling a Vehicle fact sheet (February 2025): sales tax and trade-ins
- PennDOT — Fee for Local Use: Participating Counties (August 2026)
Last verified October 19, 2026. PennDOT's own fee schedule and fact sheets. The list of counties charging the $5 fee for local use is from PennDOT's August 2026 fact sheet; counties can join with 90 days' notice, so it may grow.
Washington vehicle sales tax, title and tab fees
- Washington DOR — Motor vehicle sales/use tax (0.5% from January 1, 2026)
- Washington DOR — Motor vehicle local sales and use tax rates, October 1 – December 31, 2026
- Washington DOR — Determine the location of my sale
- WAC 458-20-247 — Trade-ins, selling price, and sales tax
- Washington DOL — Calculate vehicle tab fees
- RCW 46.17.365 — Motor vehicle weight fee
Last verified October 19, 2026. Department of Revenue, Department of Licensing, the RCW and the WAC. Local rates are from the DOR motor vehicle table for October 1 – December 31, 2026 and change each quarter. The RTA tax and local district fees depend on your address and are not modeled.
Arizona vehicle sales tax, VLT, title and registration
- A.R.S. 42-5010 — Transaction privilege tax rates (5% retail)
- A.R.S. 42-5010.01 — Additional rate of 0.6% through June 30, 2041
- A.R.S. 42-5001 — Definitions: trade-ins excluded
- A.R.S. 42-5040 — Sourcing to the seller’s business location
- A.R.S. 28-5801 — Vehicle license tax rate and value
- A.R.S. 28-2003 — Title and registration fees
- A.R.S. 49-551 — Air quality fee
- Arizona Department of Revenue — Tax rate table
Last verified October 19, 2026. The Arizona Revised Statutes, read on azleg.gov. ADOT and ADOR pages could not be read from our network, so every figure is taken from the statute itself. Local rates are entered by you from the ADOR rate table.
Michigan vehicle sales tax, trade-in credit and title fee
- Michigan Treasury — Form 485 (Rev. 1-26): 2026 trade-in allowance and 6% sales tax
- Michigan Department of State — Dealer Manual, Chapter 8: Sales Tax (Rev. 10/26)
- Michigan Department of State — Title transfer and vehicle registration
- Michigan Department of State — License plates and tabs
Last verified October 19, 2026. Michigan Treasury Form 485 (Rev. 1-26) and Department of State pages and dealer manual. The MSRP-based registration fee table in MCL 257.801 could not be read from our network, so the calculator leaves the registration fee out and links to the Secretary of State calculator instead.
Illinois vehicle sales tax, private party tax, title and registration
- Illinois Department of Revenue — RUT-5, Private Party Vehicle Use Tax Chart for 2026
- Illinois Department of Revenue — ST-556 instructions (R-12/24): dealer tax rate and trade-ins
- Illinois Department of Revenue — Retailers’ occupation and use tax rates (6.25%)
- Illinois Department of Revenue — Vehicle tax FAQs
- Illinois Secretary of State — Fees
Last verified October 19, 2026. Illinois Department of Revenue forms and guidance, including the RUT-5 chart for 2026. The Secretary of State and the Illinois General Assembly sites could not be opened from our network, so the $165 title and $151 registration are shown as published there and marked as not re-checked.
Mortgage payment, extra payment, amortization and payoff
- CFPB — How does paying down a mortgage work? (amortization)
- CFPB — What is private mortgage insurance?
- CFPB — When can I remove private mortgage insurance (PMI) from my loan?
- CFPB — What is an escrow or impound account?
- CFPB — What is a prepayment penalty?
- CFPB — Your mortgage servicer must comply with federal rules
Last verified October 19, 2026. The math is the standard fixed-rate amortization formula, worked in cents. The PMI, escrow, prepayment and servicer rules are from the Consumer Financial Protection Bureau. KnownSum does not publish mortgage rates; every calculator uses the rate you enter.
Texas vehicle tax, title and license
- TxDMV — Purchased a vehicle outside of Texas (title, registration and county fees)
- TxDMV — Register your vehicle (base registration and local county fees)
- TxDMV — Standard Presumptive Value (SPV) tool
- Texas Comptroller — Motor Vehicle Sales Tax
- Texas Comptroller — Trade-Ins (Motor Vehicle Tax Guide)
- Texas Comptroller — Standard Presumptive Value (Motor Vehicle Tax Guide)
- Texas Comptroller — Private-Party Purchases and Standard Presumptive Values
Last verified September 19, 2026. Title and local fees vary by county. Verify with your county tax assessor-collector before you buy.
How often figures are checked
Figures are re-checked against these sources at the start of each tax year, and whenever the IRS publishes a change. See the methodology page for how they are used.