Source directory

Start with the authority behind the rule

These primary references support rule-based calculators and the educational context around them. An external link is a reference, not an endorsement of this site or its result.

Last updated: July 13, 2026

Tax and payroll

2026 federal tax inflation adjustmentsInternal Revenue Service Tax Withholding EstimatorInternal Revenue Service Self-Employed Individuals Tax CenterInternal Revenue Service 2026 withholding and estimated-tax guidanceInternal Revenue Service Contribution and benefit baseSocial Security Administration

Thailand tax reference

Reference library only. Current statutory income-tax calculators are labeled for the United States and must not be used as a Thai filing calculation.

Personal income tax calculationThailand Revenue Department Personal income tax ratesThailand Revenue Department

Mortgages and borrowing

Loan Estimate explainerConsumer Financial Protection Bureau Mortgage calculator guidanceConsumer Financial Protection Bureau Mortgage and home-buying resourcesConsumer Financial Protection Bureau Should I refinance?Consumer Financial Protection Bureau What you should know about home-equity lines of creditConsumer Financial Protection Bureau Auto-loan shopping and borrower guidanceConsumer Financial Protection Bureau Truth in Lending (Regulation Z), including APR disclosuresConsumer Financial Protection Bureau FHA mortgage insurance premium structureU.S. Department of Housing and Urban Development VA funding fee and closing costsU.S. Department of Veterans Affairs

Saving and deposit accounts

Deposit account basics and protectionsFederal Deposit Insurance Corporation Deposit insurance FAQsFederal Deposit Insurance Corporation National deposit rates and rate capsFederal Deposit Insurance Corporation Share insurance FAQsNational Credit Union Administration

Investing and retirement

Financial tools and calculatorsU.S. Securities and Exchange Commission — Investor.gov Understanding feesU.S. Securities and Exchange Commission — Investor.gov Personal Social Security benefit estimatesSocial Security Administration