GRAT Calculator — Grantor Retained Annuity Trust

A Grantor Retained Annuity Trust (GRAT) transfers asset appreciation above the IRS §7520 hurdle rate to your heirs at near-zero gift-tax cost. No lifetime exemption needed. The calculator below shows your annuity payment, year-by-year trust balance, and how much moves to heirs tax-free.

GRAT calculator

Enter your asset value, expected growth, and term. The calculator computes the zeroed-out annuity payment, shows the year-by-year trust schedule, and estimates how much wealth transfers to your heirs.

How the zeroed-out GRAT works

The "gift" in a GRAT is calculated as the present value of what heirs will receive — the remainder after you've taken back all your annuity payments. In a zeroed-out GRAT, you set the annuity amount so that the present value of the remainder (discounted at the §7520 rate) equals the asset value you contributed. Gift value = $0.

The annuity formula:
Annual annuity = Asset value × §7520 rate ÷ [1 − (1 + §7520 rate)−n]

At the §7520 rate of 5.00% and a 2-year term, the annuity on a $5M GRAT is approximately $2,688,900/year. Year 1, the trust grows and pays the annuity; Year 2, same. If the asset grew at 12%, roughly $1.28M stays in the trust and passes to heirs — with no gift tax and no exemption used.

GRAT term: 2 years vs longer

Most estate planners favor short GRAT terms (2–3 years) for three reasons:

1. Mortality risk. If the grantor dies during the trust term, the full trust value returns to the estate — the GRAT fails completely. A 2-year term minimizes this risk. (2-year is the most common; some practitioners use 2-year rolling series.)
2. You can re-GRAT. When the first GRAT succeeds, use the annuity proceeds to fund a new GRAT immediately. Rolling GRATs compound the transfer effect over time without the grantor needing to stay alive for 10 years.
3. Legislative risk. Congress has periodically proposed 10-year minimum GRAT terms and minimum remainder requirements. Shorter terms lock in transfers before any legislation takes effect.

Longer terms (7–10 years) work well when the grantor is younger, the asset has stable long-duration growth, and there's no legislative concern. A longer GRAT term lowers the required annuity payment (because the IRS discounts the remainder over more periods), meaning more of the asset stays in trust if growth is strong.

Rolling GRATs

A rolling GRAT strategy involves creating a new 2-year GRAT each year, funded with the annuity received from the prior GRAT. This creates an assembly line of GRATs — some fail (no transfer), some succeed — but the ones that succeed each year collectively move significant appreciation out of the estate.

Example: Grantor funds a $5M GRAT each year for 10 years. In years where the underlying asset (say, a concentrated stock position) appreciates 15%, each GRAT transfers ~$1.6M to heirs. In down years, nothing transfers. Over 10 years in a volatile growth stock environment, rolling GRATs can cumulatively transfer $5–15M to heirs with zero gift tax and zero exemption use.

When GRATs work best

GRATs are most powerful when the asset contributed is expected to significantly outperform the §7520 hurdle rate:

• Pre-IPO equity — stock expected to 3–10× on an IPO or acquisition. Grantor funds the GRAT pre-event; the appreciation passes to heirs post-event.
• Closely-held business interests — businesses in growth phase. Contribute a minority interest (often with a valuation discount), let it appreciate, pass the appreciation tax-free.
• Real estate in appreciation markets — contributed at current value; if appreciation exceeds 5%, the surplus transfers. Particularly effective with commercial property with good NOI growth.
• Concentrated stock positions — large employer stock positions before a run-up. Combine with a collar or exchange strategy for downside protection inside the trust.

GRATs are least effective for assets with low growth expectations (treasury bonds, money market), dividend-heavy portfolios that distribute more than they appreciate, or assets where the grantor's health makes a 2+ year term risky.

GRAT risks

• Mortality risk. Grantor death during the term returns the full trust to the estate. The GRAT produces no transfer but also no loss — you've simply not moved any wealth out. Short terms and rolling structures manage this.
• Growth risk. If the asset earns less than the §7520 rate, nothing transfers. Not a loss — the annuity returns the full contributed value. But the legal fees for the trust setup are a sunk cost.
• Legislative risk. Both the Obama and Trump-era budgets proposed limiting GRATs (10-year minimum term, 10% minimum remainder). None passed. Current legislative environment has no active proposals, but the risk remains in a future Congress.
• No spousal access. Unlike a SLAT, no beneficiary access during the term. Annuity payments go to the grantor, not the spouse.

GRAT vs SLAT vs IDGT installment sale

The strategies complement each other. A common HNW portfolio: SLAT (funded with diversified assets, uses exemption efficiently) + rolling 2-year GRATs (on the concentrated stock or business interest, captures appreciation without using more exemption) + dynasty trust (as SLAT remainder beneficiary to extend across generations).