RSU Down Payment Calculator

What San Francisco buyers actually ask about RSUs

The calculator answers one question: what your vest is worth after tax. These are the questions that decide whether it becomes a house. Every figure below carries its source and the date it was checked — if a rate has changed since, the number is wrong and should be corrected rather than trusted.

Can I use my RSUs to qualify for a mortgage?

Only the vested ones, and only if the stock is publicly traded. Fannie Mae's Selling Guide (B3-3.3-07, effective 4 Mar 2026) requires that restricted stock "must have vested and been distributed to the borrower without restrictions." Unvested RSUs cannot be counted as qualifying income no matter how certain the vest looks, and RSUs granted as a sign-on bonus are explicitly ineligible.

This is the single most common surprise for pre-IPO buyers: a grant worth seven figures on paper contributes nothing to what a lender will lend until it vests, distributes, and can be sold.

How much RSU history does a lender need?

For time-based awards, Fannie Mae requires a minimum of 12 months of history with the current employer. For performance-based awards two years is the norm, though 12 months can be acceptable where other factors are positive. For a one-time time-based grant, the vesting schedule must show the income continuing at least three years past the note date.

Source: Fannie Mae Selling Guide B3-3.3-07, effective 4 Mar 2026. Freddie Mac's requirements are similar but not identical, and individual lenders layer their own overlays on top — confirm with your lender before assuming.

How is RSU income calculated for qualifying?

Not at today's share price. Fannie Mae's formula is the 200-day moving average of the share price multiplied by the vested shares distributed over the most recent 24 months, divided by 24. Where a borrower has between 12 and 24 months of history, the lender may divide by the actual number of months instead.

The practical effect: a stock that ran up in the last quarter does not lift your qualifying income much, and a stock that fell will keep dragging on it for months after it recovers. Source: Fannie Mae Selling Guide B3-3.3-07, effective 4 Mar 2026.

Why does my vest get taxed so heavily at the moment it lands?

Because RSU vesting is treated as supplemental wages, and supplemental wages are withheld at flat statutory rates rather than your marginal rate. Federal withholding is 22% on supplemental wages up to $1 million in a calendar year and 37% above it. California withholds a flat 10.23% on bonuses and stock options at all wage levels. On top of that, California SDI is 1.3% for 2026 with no wage ceiling — the ceiling was removed by SB 951 effective 1 Jan 2024, so it applies to the entire vest.

Sources: IRS supplemental wage withholding rules; California EDD, Contribution Rates and Benefit Amounts (2026 rate effective 1 Jan 2026). Verified 25 Aug 2026.

Is 22% withholding enough, or will I owe more in April?

For most San Francisco tech employees with a large vest, 22% federal withholding is not enough — it is a flat statutory withholding rate, not an estimate of what you owe. If your total income puts you in a higher federal bracket, the gap between 22% withheld and your actual marginal rate comes due at filing.

This matters for a home purchase in a specific way: money you mentally allocated to a down payment may already be spoken for by an April tax bill. Model the shortfall before you write an offer, not after. This calculator estimates withholding, which is not the same as final liability — talk to your CPA about the difference in your situation.

My RSUs are double-trigger and my company is private. What now?

Double-trigger RSUs vest on time but only convert to sellable shares on a qualifying liquidity event — an IPO, acquisition, or tender offer. Until that second trigger fires, the shares are illiquid: you cannot sell them, and a lender cannot count them as income or as reserves.

Buyers in this position typically bridge the gap another way — a larger cash down payment, a co-borrower, asset-depletion underwriting, or timing the purchase around a tender offer. Which one fits depends on your grant, your employer, and your timeline.

Should I sell at vest or hold?

That’s a question for a CPA or financial advisor who can see your whole picture. What matters for a home purchase: lenders count cash that’s in your account, and share prices can move between offer and close. If your down payment depends on shares you still hold, talk with your advisor about timing before you write an offer.