Stop the $30K April Surprise
On Your RSUs
22% withholding leaves you $20K–$30K short. See your exact gap and get pre-filled W-4 + 1040-ES forms in 60 seconds—without a $1,500 CPA.
Results in 60 seconds · Detailed analysis
RSU Withholding Analysis
$200K RSU vesting this year. How much will I owe?
Default 22% Withholding
Withheld
$44,000
Actual Tax Owed
$88,925
Shortfall Due April 15
$44,925
+ underpayment penalties
With Smart Estimates
Quarterly Estimated Payments
$11,231/qtr
Surprise Bill at Filing
$0
No penalties. No stress.
Built for equity holders at
How It Works: 3 Steps, 5 Minutes
No CPA appointment needed. No 2-week wait. Just upload your vest schedule and get actionable tax forms in minutes.
Ready to calculate your withholding gap?
Start My Free CalculationFree to calculate. Plans from $49/month for form downloads.
Try the Calculator: See Your Gap
Adjust the sliders to match your situation. This is a simplified demo—the full calculator accounts for all tax brackets, deductions, and FICA caps.
Note: This is a simplified demo. The full calculator accounts for federal tax brackets (including phase-outs), all 50 states, FICA wage base limits, itemized deductions, and multi-vest schedules across 4 quarters.
Why 22% Withholding Leaves You $20K-$30K Short
Tech employees earning $180K+ face 40-50% actual tax rates. The 22% default creates a gap that hits hard in April.
The $20K-$30K Surprise
22% withholding is too low. Your actual rate is 35-45%. Come April, you owe $20K-$30K you weren't expecting.
$20K-$30K surprise bill
The Quarterly Chaos
4-16 RSU vests per year at different stock prices. By Q4, you're underwater with no visibility.
No year-round visibility
CPA Wait Times
2-3 weeks to get a CPA appointment during tax season. By then, it's too late.
2-3 week wait
Expensive Advice
$1,500+ for a CPA to tell you how much extra to withhold from your paycheck.
$1,500+ fee
Why is 22% withholding never enough?
22% is the IRS supplemental rate—a flat rate for bonuses and RSUs. But it's not your actual tax rate. Tech employees earning $180K+ pay 40-50% in taxes (federal + state + Medicare). But only 22% gets withheld. That 20-30% gap = $20K-$30K you owe in April.
One Wrong Move Could Cost You $20K-$30K
You need your exact withholding gap. Not a guess. Not “sometime next month.”Right now.
Stop guessing. Calculate your exact withholding gap in 5 minutes.
Show Me How →Stop Guessing: Your Complete Tax Action Kit
Pre-filled forms ready to submit—no CPA appointment required
Form W-4 (Pre-Filled)
Employee's Withholding Certificate
Department of the Treasury - Internal Revenue Service
- Print this form
- Sign and date
- Submit to your employer's HR/payroll department
- Withholding changes take effect next paycheck
Form 1040-ES Vouchers (Pre-Filled)
Estimated Tax Payment Vouchers
Sample form preview
Your forms will be pre-filled with your exact amounts
Your Report Includes:
- Withholding Gap Analysis (The Main Answer)
Exact dollar amount you'll owe beyond 22% withholding, broken down by quarter
- Pre-Filled Form W-4 (2024/2025)
IRS Form W-4 with exact additional withholding amount filled in. Print and submit to HR.
- Pre-Filled 1040-ES Vouchers
All 4 quarterly estimated tax payment vouchers with mailing addresses and amounts
- Full Tax Breakdown
Federal tax, state tax, FICA (Social Security + Medicare), effective rate, marginal rate
Can I really update my W-4 myself?
Yes. Form W-4 has a section (Step 4c) for extra withholding. We calculate the exact dollar amount and fill it in for you. Just print, sign, and give to HR. Takes 5 minutes.
Share with your CPA: Many customers validate our calculation with their tax professional. 30-day money-back guarantee if your CPA finds any errors.
Simple, Transparent Pricing
Choose the plan that fits your situation. All plans include 30-day money-back guarantee.
Yearly
Just $12.42/month
- Full withholding gap analysis
- Pre-filled W-4 + 1040-ES forms
- 3 remediation strategies compared
- Detailed tax breakdown
- IRS-based tax calculations
- Unlimited recalculations (critical for quarterly vests)
- Access to all 5 calculators (RSU, ISO, Multi-Year, 83(b), IPO Lock-Up)
- Track vests across multiple grants
- Email reminders for Q4 deadlines
- Save $439 vs monthly
Why Annual Makes Sense for RSU Holders
Your situation changes throughout the year:
- New RSU vests every quarter
- Stock price changes each vest
- Salary increases (promotions, raises)
- Bonuses and refresher grants
Recalculate whenever you need:
- After each quarterly vest
- When stock moves +/- 20%
- After promotions or raises
- Before filing taxes in April
Most RSU holders recalculate 3-4 times per year. Monthly ($49) × 4 = $196. Annual plan ($149) saves you money and includes access to all other calculators.
30-day money-back guarantee. If our calculation doesn't match your CPA's analysis or you're not satisfied for any reason, we'll refund you immediately—no questions asked.
Or try the free calculator first — no credit card required
Just need one calculation? Unlock the exact result for $29 — no subscription.
CPA-Grade Accuracy. No CPA Price Tag.
Every calculation follows IRS Form 6251 line by line — the same methodology your CPA uses.
Cost
Time to get answer
Multiple scenario modeling
Accounts for state taxes
CPA-ready report
Accuracy for complex situations
30-Day Money-Back Guarantee — If your CPA disagrees with our numbers, full refund. No questions asked.
Your money is safe
256-bit encryption
Every connection encrypted end to end.
Payments via Stripe
We never see or store your card details.
30-day money-back
Full refund, no questions asked.
Every number is sourced
Cited to IRS & state DOR
Every figure traces to an official table.
We never sell your data
No account needed to calculate.
Built for Engineers Who Hate Tax Surprises
Common scenarios where knowing your true withholding gap matters
The W-4 Optimizer
Situation
High earner in CA/NY, quarterly RSU vests worth $40-80K/year
Challenge
22% supplemental withholding leaves them owing $15-30K every April—a nasty surprise they can't afford
How They Use It
Calculate exact W-4 additional withholding to hit near-zero at filing
“File with confidence, not a check”
The Multi-Vest Tracker
Situation
4-12 RSU vests per year at different stock prices, plus salary, bonus, spouse income
Challenge
Each vest looks manageable, but cumulative impact pushes them into higher brackets—Excel can't handle this
How They Use It
Model all vests together to see true annual tax impact and bracket creep
“See the whole picture, not just one vest”
The Q4 Estimator
Situation
November/December, realized withholding won't cover their tax bill
Challenge
January 15 deadline for 1040-ES, but no idea how much to pay
How They Use It
Get exact Q4 estimated payment amount or last-minute W-4 adjustment
“Hit the deadline, skip the penalty”
Sound familiar? Calculate your exact withholding gap—no spreadsheets, no surprises.
Calculate My Withholding GapJust want the dollar gap? Try our free RSU Withholding Shortfall Calculator — it shows the gap between the flat 22% your employer withholds and your real marginal-bracket tax, plus FICA, state tax, and the penalty, in seconds.
Don't Be the Engineer Who Owes $30K in April
See your exact withholding shortfall — before April 15 catches you off guard.
IRS-based methodology · 30-day money-back guarantee · Results in 60 seconds
RSU Tax Calculator FAQs
Common questions about calculating your RSU withholding gap
60 seconds. No credit card required.
Still have questions? Our support team is here to help.
Contact Support →One Platform for Your Entire Equity Journey
From your first ISO grant to IPO lock-up expiration — every tax decision, one subscription.
5
Calculators
Unlimited
Calculations
$149
per year