Know your withholding is on track before tax time.
W4Pilot estimates the federal, state, Social Security and Medicare taxes taken from each paycheck, tracks them through the year, and shows how to adjust your W-4 so you don't face a surprise bill in April or give the IRS an interest-free loan.
14 days free on every plan. Cancel before the trial ends and you pay nothing. We never ask for your Social Security number.
Example: $2,000 every two weeks, single, Texas, 2026
Illustration using 2026 IRS brackets and the standard deduction. Your results depend on your own pay and W-4.
How it works
A few minutes with your latest pay stub is all it takes.
Enter your paycheck
Type in your pay and W-4 choices, or scan a photo of your pay stub on the Plus plan and up.
See the full picture
W4Pilot estimates federal, state, Social Security and Medicare for the whole year and compares it with what's being withheld.
Adjust with confidence
Try W-4 changes in the simulator and see the new take-home pay before you give your employer a new form.
Built for the paychecks other tools skip
Every plan covers a regular W-2 paycheck. Pro and International add the situations most withholding calculators leave out.
See where each dollar goes
Federal and state withholding for all 50 states and DC, a year-to-date tracker, and a simulator that shows the effect of changing your W-4.
Housing allowance, done right
Work out how much of your housing allowance is tax-free, your self-employment tax on ministerial pay, and the effect of a Form 4361 exemption.
Foreign income in one place
Compare the foreign earned income exclusion with the foreign tax credit, check the residency tests, and see when FBAR and FATCA reporting applies.
What's inside
Tax figures are updated every year, and each change is listed in the app.
- Paycheck calculatorFederal, state, Social Security and Medicare, using current-year IRS figures.
- Year-to-date trackerLog each paycheck and watch your withholding add up against your estimated tax.
- Withholding simulatorSee what extra withholding or new dependents do to each check, plus a safe-harbor check.
- Pay stub scanSnap a photo and W4Pilot reads the pay amounts. It never asks for names or ID numbers.
- Side income & investments1099 and self-employment tax, capital gains, dividends, retirement income and more.
- Credits & changes referenceThis year's credits, limits and law changes side by side with last year's.
Plans and pricing
Every plan starts with a 14-day free trial. Cancel before it ends and you pay nothing.
Pay by card, PayPal, Apple Pay or Google Pay. Checkout is handled by Paddle, our Merchant of Record, which adds any sales tax that applies. Full refund within 30 days of your first payment.
Questions
Is W4Pilot tax advice?
No. W4Pilot gives estimates for planning. It doesn't prepare or file tax returns and isn't affiliated with the IRS. For big decisions, check with a qualified tax professional.
Will you ask for my Social Security number?
Never. W4Pilot doesn't ask for Social Security numbers, taxpayer IDs, bank or card numbers, and its boxes refuse anything shaped like a Social Security number.
Who can see my numbers?
Only you. Each account can read and change only its own records, and that rule is enforced by the database itself. We don't sell your information or use it for advertising. See our Privacy Policy.
How does the free trial work?
Every plan starts with 14 days free. If you cancel before the trial ends, you aren't charged. If you keep going, your first payment is charged when the trial ends.
What if it isn't right for me?
Ask within 30 days of your first payment and we'll refund it in full, no reason needed. See our Refund Policy.
Which plan do I need?
Starter covers one regular paycheck. Plus adds pay stub scanning and the withholding simulator. Pro adds clergy income, side income, investments and multi-state situations. International adds foreign income, residency tests, FBAR and FATCA.
I'm a minister. Does it handle housing allowance?
Yes, on the Pro plan. It estimates the tax-free part of your housing allowance, self-employment tax on ministerial earnings, and the effect of an approved Form 4361 exemption.
Will the tax figures stay current?
Yes. W4Pilot is updated for each new tax year once the IRS publishes the new figures, and each change is listed on the Credits & Changes page.
Can I use it on my phone?
Yes. W4Pilot runs in the web browser on phones, tablets and computers. Apple App Store and Google Play versions are planned.
The checkout window won't open. What can I do?
Some VPNs, ad blockers and browser privacy settings block the secure checkout. Pause your VPN or ad blocker for w4pilot.com, or try another browser or your phone. Still stuck? Email info@w4pilot.com.
How do I reach you?
Email info@w4pilot.com. For plan and pricing questions, sales@w4pilot.com.
Start your free trial today
Every plan starts with 14 days free. Early-adopter prices are available for the first 500 customers or until April 15, 2027.