What your Roadster deposit really costs
What it could earn while you wait.A refundable deposit still ties up your money. This shows what the same dollars could have earned in Treasury bills or an S&P 500 index fund over the same months. It works for any pre-order deposit: pick Other.
Given up by Jun 2028, in T-bill interest
$3,532
Estimate4.18% for 20 monthsTreasuryToday's 13-week T-bill rate (4.18% on Oct 16, 2026), assumed constant. It won't be. Taxes and inflation are left out. Not financial advice.
or $8,626 in the S&P 500
What 2017 reservers already gave up
- In an S&P 500 fund
- $94,766
- In T-bills
- $11,577
Historical dataJan 2018 to Dec 2025, annual returnsDamodaran's annual S&P 500 (with dividends) and 3-month T-bill returns for 2018 to 2025, chained year by year. Nov and Dec 2017 and 2026 so far are not included, so the real figure differs a little.
No car yet. Some holders struggled to get refunds, Electrek reports (opens in a new tab).
| Year | S&P 500 | T-bills |
|---|---|---|
| Deposit | $50,000 | $50,000 |
| 2018 | $47,885−4.23% | $50,985+1.97% |
| 2019 | $62,830+31.21% | $52,061+2.11% |
| 2020 | $74,152+18.02% | $52,248+0.36% |
| 2021 | $95,263+28.47% | $52,269+0.04% |
| 2022 | $78,077−18.04% | $53,362+2.09% |
| 2023 | $98,424+26.06% | $56,179+5.28% |
| 2024 | $122,912+24.88% | $59,089+5.18% |
| 2025 | $144,766+17.78% | $61,577+4.21% |
| End of 2025 | $144,766 | $61,577 |
| Given up | $94,766 | $11,577 |
| Car delivered | Not yet | |
How the cost is calculated
The formula, worked examples, a year-by-year table
A reservation deposit doesn't earn interest while it waits. The cost of waiting is what the same money would have earned somewhere else over the same months. We compound once a year and allow part years:
Given up = deposit × (1 + yearly return)months ÷ 12 − deposit
- Months parked. From the month you pay to the month you get the car or your money back. October 2026 to June 2028 is 20 months, or 1.67 years.
- Yearly return. Today's 13-week Treasury bill rate (4.18% on Oct 16, 2026) for the headline, because it is the safe place to park cash. For comparison, the S&P 500 with dividends averaged 10.02% a year from 1928 to 2025 and 12.37% from 1975 (geometric averages of Damodaran's annual data).
- Rounding. Whole dollars, half up.
Worked example. $50,000 paid in October 2026, car in June 2028: $50,000 × 1.041820/12 = $53,531.65, so the T-bill interest given up is $3,532. At 10.02% it is $8,626. For the $250,000 Thrust tier the two numbers are $17,658 and $43,129.
The 2017 receipt is history, not a scenario: it chains the actual annual returns for 2018 through 2025, so a $50,000 deposit's alternative is 50,000 × 0.9577 × 1.3121 × … × 1.1778 in the S&P 500 column.
| Car arrives | T-bills (4.18%) | S&P 500 (10.02%) |
|---|---|---|
| Jun 2028 | $3,532 | $8,626 |
| Dec 2028 | $4,639 | $11,493 |
| Dec 2029 | $6,923 | $17,655 |
| Dec 2030 | $9,302 | $24,434 |
| Dec 2032 | $14,364 | $40,097 |
| Dec 2035 | $22,777 | $69,985 |
Left out on purpose: taxes on interest and gains, inflation, and the few days between the $5,000 card payment and the wire. We count the whole deposit from the month you pay.
Questions
Refunds, the 2017 reservers, why T-bills, taxes
How much interest do I give up on a $50,000 Roadster deposit?
About $3,532 if the car arrives in June 2028 and you paid in October 2026, using today's 13-week Treasury bill rate of 4.18% (Oct 16, 2026) held for 20 months. If you wait until December 2028 it is about $4,639. In an S&P 500 index fund at its 10.02% long-run average the same 20 months come to about $8,626, but stocks can also fall.
What does the $250,000 Thrust deposit cost while I wait?
About $17,658 in T-bill interest from October 2026 to June 2028, or about $43,129 at the S&P 500's long-run average. At 4.18%, each extra year of waiting adds more than $10,000 on $250,000.
What did people who reserved in 2017 give up?
A $50,000 deposit paid in November 2017 would have grown to $144,766 in an S&P 500 fund by the end of 2025 ($94,766 more than the deposit) or $61,577 in T-bills ($11,577 more). For the $250,000 Founders Series it is $473,831 and $57,884. These use annual returns for 2018 to 2025 only.
Is the Roadster reservation refundable?
We don't decide that, and neither does this calculator. News reports describe the first $5,000 card payment as “fully refundable”. The reservation agreement, as quoted by tesla-roadster.info, says Tesla “cannot guarantee when … or if it will be delivered”. Electrek reported that some 2017 holders had trouble getting refunds. The agreement you sign governs.
Why use the T-bill rate for the headline number?
Treasury bills are the closest thing to parking cash safely: short, backed by the U.S. government, and easy to buy. The 13-week coupon-equivalent rate was 4.18% on Oct 16, 2026. We assume it stays there, which it won't, so the result is an estimate. It is the cautious number; stocks usually earn more over long periods but not every year.
Where does the 10.02% S&P 500 return come from?
It is the geometric average of the S&P 500's annual returns with dividends from 1928 to 2025, from Aswath Damodaran's data at NYU Stern (we compute it ourselves: 10.018%). Since 1975 the same average is 12.37%. It is a long-run average, not a forecast. In 2022 the index lost 18.04%.
Does this include taxes or inflation?
No. T-bill interest is taxed federally and fund gains are taxed when you sell, and inflation shrinks every dollar on both sides. Leaving them out keeps the comparison simple: the same pre-tax dollars, held two different ways.
Can I use this for another pre-order or a different deposit?
Yes. Pick Other, type any amount from $100 to $10,000,000, set the month you paid and the month you expect delivery. It works for any big deposit that sits without earning interest: a car, a house build, a tuition hold.
What the reservation terms say
Quoted from the sources, nothing added
We don't say whether a deposit is or isn't refundable. Here is what the sources say, word for word where we quote:
- The new reservation starts with a $5,000 card payment that news reports call “fully refundable”, followed by a $45,000 wire within 10 days for Performance, or a $245,000 second payment for Thrust (Electrek, Fortune).
- The reservation agreement, section 4, as quoted by the fan site tesla-roadster.info: Tesla “cannot guarantee when … or if it will be delivered”.
- The first Roadster deposits were taken in November 2017, with production promised for 2020. The new target is 2028.
Read the agreement you are offered before you pay. Its terms, not this page, decide refunds.
Sources and fine print
Treasury, NYU Stern, the news, checked dates
13-week T-bill rate, 4.18%
Coupon equivalent on Oct 16, 2026, latest row of the 2026 daily bill rates.
U.S. Department of the Treasury (opens in a new tab) · Checked
OfficialS&P 500 and 3-month T-bill annual returns, 1928 to 2025
Updated Jan 5, 2026. Averages computed by us: 10.02% (1928 on), 12.37% (1975 on).
Published dataFortune: Tesla's flying Roadster, 2028 production and price (Oct 17, 2026)
Performance $50,000, Thrust $250,000, production target 2028; 2017 promise was 2020
ReportedElectrek: Tesla reopens $50,000 Roadster reservations (Sep 20, 2026)
$5,000 card + $45,000 wire; 2017 holders still waiting, some reported refund trouble
ReportedThe Verge: Tesla re-opens $50,000 reservations for its next-gen Roadster
Reportedtesla-roadster.info: reservation agreement quoted (fan site, checked Oct 16, 2026)
§4: Tesla “cannot guarantee when … or if it will be delivered”
Reported
Not financial advice. Past returns don't predict future ones, and today's T-bill rate will change. Not affiliated with Tesla, Inc.
Privacy: everything you enter stays in this browser. Nothing is uploaded or saved, and the page only counts which tier was looked at, never an amount.