RSU Multi-Year Tax Projection Calculator (2026–2030)

Most executives receive a new RSU grant every year. After three or four years on the job, you have three or four tranches vesting simultaneously — and the total ordinary income can be dramatically higher than any single grant implies. A $400K annual grant feels manageable. Four of them vesting at once in year four does not.

This calculator lets you enter up to four overlapping RSU grant tranches alongside your base compensation and see the year-by-year tax picture: total ordinary income from RSUs, the 22% supplemental withholding gap (the difference between what's withheld and what you actually owe), and the peak year where your estimated tax payments will be largest.

Why multi-grant stacking is the biggest underestimated tax risk in executive comp

An executive who joins a company in 2023 and receives an annual grant every year accumulates tranches as follows:

In 2026, four separate tranches vest in the same calendar year. If each grant is worth $300K/year, total RSU ordinary income hits $1.2M in a single year — on top of base salary and bonus. The 22% supplemental withholding covers only a fraction of what the IRS will want.

The 22% withholding gap: how much you actually owe vs. what's withheld

When RSUs vest, your employer withholds federal income tax at the supplemental wage rate of 22% (for most employees) or 37% (for supplemental wages over $1M in a calendar year). For C-suite executives with total W-2 compensation above $1M, the 37% rate may apply to the RSU portion — but below that threshold, 22% is typical.

The problem: most senior executives face combined federal marginal rates of 35–37%. The gap is 13–15 cents per dollar of RSU income — every year, on every tranche.

Add California at 13.3% and the shortfall on $1M of RSU income rises to $283,000 — with zero of the state tax automatically withheld unless you set up CA withholding explicitly.

How to use this projection

The output table shows your tax true-up for each year from 2026 to 2030 — the amount you should set aside or pay in quarterly estimated taxes to avoid underpayment penalties. IRC §6654 requires quarterly estimated payments if you expect to owe $1,000+ after withholding; and your safe-harbor amount is the lesser of 90% of this year's tax or 110% of last year's tax (the 110% threshold applies if prior-year AGI exceeded $150,000).

What this calculator does not model

• FICA taxes. Social Security (6.2%) applies only up to the 2026 wage base of $184,500. Once salary exceeds $184,500, RSU vests have no SS exposure — but the 1.45% Medicare tax (plus the 0.9% Additional Medicare Tax above $200K single / $250K MFJ) applies to all RSU income.
• Alternative Minimum Tax (AMT). RSUs and NSOs are ordinary income and do not create AMT preference items. ISOs do — see our ISO AMT calculator for that analysis.
• Net Investment Income Tax (NIIT). RSU vest income is ordinary income, not investment income, and is not subject to the 3.8% NIIT. However, subsequent gains on shares held after vesting are subject to NIIT above the $200K / $250K MAGI threshold.
• Intra-year income bunching. This model uses annual income. If multiple large grants vest in the same month, it can push you into higher brackets faster than spread vesting. The annual result is the same; the estimated-tax timing may differ.
• Share price changes. This calculator uses a fixed annual vest value per grant. If your employer stock rises or falls, actual income will differ. Consider running conservative and optimistic scenarios.
• State tax nuance. California taxes RSU income based on the grant-to-vest period (not just where you live at vest). If you moved states during a grant period, a blended rate applies. See our multi-state equity tax guide and equity relocation calculator.

Planning strategies for multi-grant RSU income

1. Maximize NQDC deferral in peak vesting years

If your NQDC plan allows deferral of a percentage of RSU proceeds upon settlement (some plans permit this — check your plan document), high-vesting years are the most efficient time to defer. The NQDC deferral offsets the income stacking from simultaneous tranches. A $300K deferral election in a year where $1.2M of RSUs vest reduces the peak-year bill meaningfully. See our NQDC vs. 401(k) allocation guide.

2. Accelerate charitable giving in peak years

A donation to a donor-advised fund (DAF) in a peak RSU year converts the contribution to an itemized deduction, potentially overcoming the standard deduction hurdle in a way that spreading giving across multiple years would not. The 60% AGI deduction limit for cash to a DAF (30% for appreciated stock to a DAF) means multi-million peak-income years have proportionally more deduction capacity. See our charitable giving guide for executives.

3. Time Roth conversions in light vesting years

Years where fewer grant tranches are active — typically the last 1–2 years before a tranche expires — are natural windows for Roth conversions. The income is lower, the marginal rate is lower, and converting traditional IRA or 401(k) balances at 24–32% rather than 37% is material over a long horizon. See our Roth conversion planning guide.

4. Plan estimated tax payments proactively

Use this projection at the start of each year to calculate your annual estimated tax liability. Divide by four for equal quarterly payments, or use the annualized income installment method (Form 2210) if your income is lumpy within the year. Underpayment penalties currently run at the federal short-term rate plus 3% — not catastrophic, but avoidable.