Where our numbers come from, how we check them, and what we do when we get one wrong.
A pay calculator is only useful if the rates and the math behind it are right. This page sets out how we build the tools on PaystubTools, the published sources we check our figures against, how often we review them, and the policies that keep advertising separate from the results you see.
None of the formulas here are proprietary. Gross pay minus pre-tax deductions, federal income tax, FICA, and state tax leaves net pay, and we show that arithmetic on each tool. FICA is the employee share of payroll tax: Social Security at 6.2 percent on wages up to the annual wage base, plus Medicare at 1.45 percent on all wages, for a combined 7.65 percent. An Additional Medicare Tax of 0.9 percent applies to wages over $200,000 for single filers and $250,000 for married couples filing jointly. Federal income tax is figured on taxable income after the standard deduction using the progressive brackets, so only the dollars within each band are taxed at that band's rate. Overtime follows the federal Fair Labor Standards Act: at least 1.5 times the regular rate for hours worked over 40 in a workweek. We use the same calculations a payroll clerk would, and we publish a worked example on each page so you can follow it by hand.
Where a figure is set by law or changes each year, we check it against a primary source and cite it on the page. The ones we lean on most:
When a figure is year-specific, like the wage base or the standard deduction, we state the year rather than implying it is fixed. If we cannot confirm a current-year number, we use the most recent confirmed year and say so.
Our tools size up a paycheck or a pay decision. They are not a payroll system, a tax return, or legal advice. A real check depends on your W-4 entries, local taxes, post-tax deductions, retirement and health benefits, and your state's actual tax schedule rather than the flat rate our tools accept. State income tax in particular varies widely, and several states have no income tax at all. For exact withholding or anything that affects what you owe, check your pay stub and W-4 and consult a tax professional or your state labor department.
Each tool and guide is reviewed when we publish it and again whenever a rate changes, a reader flags a problem, or the IRS, the Social Security Administration, or the Department of Labor revises a figure. Payroll numbers are reset on a yearly cycle, so we revisit the wage base, the standard deduction, and the brackets after each annual release. Editorial standards across the network are maintained by Chris Terry, who owns and operates the site through Encore Promotional Products.
If a calculator returns a wrong result or a page states a number you can show is off, email us and we will check it against the source and fix it. We would rather correct a figure quickly than defend a bad one. There is no form to fill out and no account to create. The fastest way to reach us is the contact page.
PaystubTools is free to use and pays for itself through display advertising and a small number of affiliate links. If you click an affiliate link and make a purchase, we may earn a commission at no additional cost to you. Advertising and affiliate revenue never influence the rates, the formulas, or the recommendations in our tools and guides. Ads are labeled, and the affiliate disclosure appears at the foot of every page.