About QuickTools

Last updated: 5 October 2026

What this site is

QuickTools is a small collection of free online calculators and converters: a US paycheck tax calculator covering all 50 states plus DC, a mortgage calculator, a unit converter, an age calculator and a BMI calculator. Every one of them runs entirely in your browser.

Why it is free

QuickTools is currently free, with no accounts, advertising or paid plans. Future changes to the business model will be explained here before launch. Calculator inputs are processed in your browser.

How we keep the numbers right

Federal tax uses IRS 2026 brackets and the SSA 2026 wage base. Employee traditional 401(k) contributions reduce the modeled income-tax base but remain subject to Social Security and Medicare.

State rate tables and modeled allowances start from Tax Foundation’s February 11, 2026 snapshot, with official Ohio, Georgia and South Carolina updates. They are a simplified planning model, not a complete tax return or withholding engine. Each tax page explains its sources and exclusions.

Mortgage payments use the standard amortization formula with the contract interest rate. BMI is an adult screening measure. Age calculations use calendar dates, with February 29 birthdays observed on February 28 in non-leap years.

What we do not model

The tax model estimates one employee’s wages using single or married-joint filing status. Spousal earnings, dependents, credits, most phase-outs, state payroll/benefit deductions, federal-tax deductibility adjustments and W-4 withholding are not modeled. Local tax is an optional user-supplied rate applied to income after the modeled 401(k) deduction. No local rate is automatically selected. Mortgage estimates exclude loan fees, PMI and changes in taxes, insurance or interest rates. Results are estimates for comparison and education.

Corrections

If you find a number that looks wrong, tell us. Tax brackets change every January and we would rather fix an error than have you rely on it. Use the contact page.

Independence

QuickTools is not affiliated with the IRS, SSA, any state revenue department or lender. There are currently no paid endorsements or affiliate links.